I Screen, You Screen: a Guide to the DIY Screen Printing Process 
By Jared Friedman 
First thing to do is get yourself a screen. Screen frames come in two main flavors, aluminum and wood. Aluminum is a little bit more expensive, quite a bit lighter, and holds its shape indefinitely. Wood is cheaper, heavier, and can start to warp after a while (a long while – I use nearly all wood screens, and in the last three years haven’t had a problem with warping yet). But either is perfectly acceptable, unless you plan on restretching your screens when you’re done with them, in which case stick with wood. 
Both frame types are available in a wide variety of sizes, starting at about 8” x 10” and going all the way up to 4’ x 6’ or larger. Lengths are usually given in outside dimensions (i.e. along the outer edge of the frame), but of course, what concern us are the inner dimensions. To be safe, subtract 4” from the outside numbers to get the inside numbers.  
You want the screen to be at least 3” larger on all sides (on the inside of the frame) than the design you want to print, but not too much larger than that – remember, the bigger the frame, the more of a pain it is to lift, store, clean, restretch, etc. And they get rapidly more expensive as they increase in size. For t-shirts, unless the print is crazy big, I usually use 18” x 20” screens.  
The other component of the screen is mesh, attached either with staples (on wood only, for obvious reasons) or glue. Mesh also comes in two types: monofilament and multifilament. They have their different uses, but suffice it to say that unless your job is highly exacting, either one will probably do just fine – use whichever is cheaper or easier to get a hold of.  
Different meshes have different numbers, which in the case of monofilament fabrics correspond to thread counts. The rule of thumb is, for both types, the higher the mesh number, the less ink it will allow to pass through the screen, but the greater the level of detail it will support. Mono numbers run from 60 (very open, great for printing big thick ink layers, not so much for fine detail) to well over 300 (rich detail, but a bit harder to squeeze ink through). If you’re using multifilament mesh, numbers end in “xx” - they go from 4xx (basically the same as 60) up through 30xx and higher.  
Generally, when printing t-shirts, and especially if it’s your first time, go with something like a 110 or 10xx mesh. The weave of the shirt itself probably won’t support too much more detail than that anyway, and you want to maximize the amount of ink that ends up on or in the fabric, since bold generally beats subtle when it comes to t-shirts.  
So go buy yourself a screen. You can probably find one at your local art/craft supply store, or you can buy one online from any of the folks listed in the resources section of this article. 
Well, I admire your pluck. Stretching your own screens will save you money, and while I wouldn’t exactly call it fun, it’s not very difficult or time-consuming once you get the hang of it. 
But you need to use real stuff to do it properly – real mesh and a real frame made for screen printing. There’s one webpage that suggests you should stretch pantyhose over an embroidery hoop. When I think about that I have to go sit by myself in the corner and cry until the feeling passes. There are aspects of this process that are perfectly acceptable, even virtuous, to half-ass; this is eminently not one of them. If you start with materials that are not designed for the job you are doing, every step the rest of the way will be ten times more difficult.  
Okay – mesh – pick the type and fineness you want. Frame – pick the size you want (and, just to reiterate, you want a wood frame – pine is awesome, hardwood not so much, since you’ll be stapling it). Buy ‘em at a screen shop, a really well-stocked art-supply store, or online.  
Get yourself a staple gun and a bunch of staples.  
You’re also going to want something called staple tape, which will prevent the staples from tearing the mesh, and also make it easier to remove them from the screen when you want to restretch it. Staple tape is a non-sticky cloth tape that’s sold at screen supply shops, and while it’s definitely a useful thing to have on hand, other items will do the same job. I think they sell something similar for sewing, or in a pinch, you can fold strips of duct tape in half lengthwise (to get rid of the stickiness – sticky tape will be a headache on this job). 
So you’ve got all of your supplies – good. Cut out a rectangle of mesh that’s about two inches wider than the narrower dimension of your frame and about four inches longer than the longer dimension – so if you’re stretching an 18x20 screen, your mesh will be 20x24.  
Cut four pieces of staple tape (or whatever you’re using) to the lengths of the frame – so in this example, two 18 inch strips and two 20 inch strips. 
Put the frame on a sturdy surface with a long edge facing you (in “landscape” format, if that helps at all), and drape the mesh over it so that one of the longer edges is flush with the side nearest you, and there’s about two inches of overhang around every other edge. 
Take a piece of tape and place it along the edge nearest you, more or less in the middle of the wood. Put a staple (or, better yet, two staples in an “x”) in the middle of the tape, through the mesh and into the frame.  
Pull the mesh (you don’t need to pull the tape) taut along the edge in whichever direction you prefer – at this point you’re only stretching it along the bar, not across anything. Without relaxing the tension, put a row of staples (about one every three-quarters of an inch, angled diagonally) along the tape, working out from the middle. Then flip it around and do the same thing in the opposite direction, working out from the middle to the other side of the bar. Presto! One side of your screen is stretched. 
Next, rotate it 180 degrees and pull the mesh taut across the screen, from the middle of the new side. Put down another piece of tape and staple it in the middle. Then do exactly as you did with the first side, except that this time, you’ll be pulling both along the edge (against the staple you just put in the middle) and across the screen (against the first edge you stapled) – i.e. pull diagonally while you staple horizontally. 
Now turn the screen 90 degrees (in either direction, it doesn’t really matter) and stretch the first short side. By this point, the mesh should be tight across the screen between the two sides you just stapled, so you can pretty much pull straight down. Put down a piece of tape, pull across the screen, and staple the whole edge (left to right, right to left, or middle out – whatever you prefer).  
Then turn the screen another 180 degrees and do the exact same thing to it. 
Now you have a screen. Try bouncing a quarter off it. If it bounces, assume a look of smug superiority – your screen is awesome, and you saved yourself about ten bucks.  
The stencil can be an actual stencil, or (as is the case 99.9% of the time) you can make the stencil in your screen.  
When I made my very first t-shirts, I cut stencils out of big sheets of plastic (they were actually old x-rays), taped them to the screen and printed. It worked really well, except that they were subject to all the limitations of actual stencils – i.e. that everything had to be connected in the design. If you’re using a physical stencil, you can skip to the section called “PRUNT UT!!” 
When you make a “stencil” in the screen, of course, the mesh connects all the elements of the design, freeing you to use as much detail as you like.  
There are two main ways to accomplish this – you can either draw your design onto the screen with something that blocks ink (called “blockout” or “screen filler”) or (again, 99.9% of the time) you can use photo emulsion to transfer a design into the screen photographically.  
Blockout is rather difficult to use – mesh is not an ideal surface for painting anything onto (given that it’s full of holes) and it’s something of a pain to wash out if you mess anything up. But it is definitely an art medium, and if you feel like making your image by hand right in the screen, by all means, you should. It’s fairly simple to use, and if you follow the instructions on the jar, you should be all set. I have no particular insights into the process, especially since the last time I used it, I was 14. 
If you’re using blockout, go ahead and skip to the printing section. 
Vastly more common is the photographic process, for reasons that should be apparent – it offers total control over the image, and once you know how to make the screen, the process is the same every time.  
You will need: 
Your image on a FILM of some sort (I’ll explain in a sec) 
A fairly powerful source of LIGHT 
A source of WATER – either a garden hose, a big sink with a hose attachment, or, in a pinch, a shower. 
1) Make your film 
Your film (also called a “positive” or, to be extra-thorough, a “film positive”) contains the image you want to print; it can be anything from a computer-printed transparency to a piece of paper to a physical object (I’ve seen some really cool screens made with pieces of lace) but for the sake of clarity, I’m going to call it “film” from now on.  
Before we get into what makes a good film, we need to backtrack a little bit and talk about how photo emulsion works. Stencils are made up of open and blocked areas – places the ink can pass through and places that it can’t. Photo emulsion works by hardening when exposed to light and remaining soluble when not. Images are transferred to the screen by shining a light through the film onto the emulsion; wherever light can pass through the image (clear areas), the emulsion hardens; where it can’t (black areas) it doesn’t. Once the screen is exposed, it’s washed in water, and whatever hasn’t been exposed washes right out, leaving an open area in the mesh for the ink to go through. 
So we can see that a good film is made up of areas of pure black (where you want ink to go) and pure white/clear (where you want ink not to go).  
There are a number of ways to make your film, with the most common being drawing or printing out from a computer. Drawing is simple enough – get a transparent sheet that will take ink and draw your image on it in black, making sure that the pen you are using is as opaque as possible.  
You can also draw your image on paper, though this presents a little more of a problem, since the “clear” areas won’t be 100% clear and the black areas will probably also let some light through. If you do use paper, consider using tracing paper, or rubbing the back of your paper with a little cooking oil, which will increase transparency.  
Printing your image out from the computer is a lot more common these days, for obvious reasons. Using the computer, you can take essentially any design and guarantee that it’s set up properly for screen printing; you can also break down photographs and other shaded images into halftones. Halftones take gray areas (which ordinarily can’t be transferred to a screen) and break them down into discrete spots of black and white (which can). Look very closely at a newspaper photo and you’ll see what I mean. 
Naturally, your best friend, when it comes to setting up images on the computer, is Photoshop. Here’s how I set up a piece of line art (i.e. an image that’s already all black-and-white, with no grays, halftones, other colors, etc.) for printing, in order to make sure that the “black” areas are really black (and not just dark gray) and the “white” areas are really white (not light gray), both of which can mess up your film without you necessarily knowing it until it’s too late. 
I) Scan your image at 300 dpi (or greater if you’ll be increasing the size). 
II) Adjust the image size to the print size you want at 300 dpi. 
III) Using the magic wand, select all the black lines/areas in the image. 
IV) Make a new layer. 
V) Using the paint bucket (and making sure the color is set to blackest black), fill the selected area on the new layer. 
VI) Make a new layer underneath the one you just filled with black lines. 
VII) Fill the new layer with whitest white. 
VIII) Flatten your image. 
Hooray! Your image is now “camera-ready,” as we say, and it took you all of three minutes. Which is not to say that you’re done. You should also make sure that everything in your image is going to print through the screen.  
Most important is to ferret out lines that are too fine – I generally say fatten them up (with the paint bucket or the “stroke” command) if they’re less than three pixels wide at 300 dpi, especially if you’re not very comfortable yet with the setup you’re using to expose the screen. Fine lines are the first things to go when you accidentally overexpose your emulsion. 
But say you need to halftone something – fair enough. Here’s how I do it. Note that the “color halftone” filter here is generally more trouble than it’s worth.  
Also note that you generally don’t need or want to halftone solid lines or black areas – that just makes them look funny. If your image is a mix of lines and grays, follow the process above before pasting the halftone back in. 
I and II) As above 
III) Take the image that you need to halftone (could be your whole design, or could be just a part of it) and highlight the whole thing. 
IV) Cut-and-paste it onto a new document. (You can skip this step if your whole image is going to be halftoned) 
V) Make sure the new document is set to “grayscale,” and then change the mode to “bitmap.”  
VI) There will be a series of menus: 
A) The program will ask what dpi you want it to output your halftone at; make sure it’s the same resolution you’re inputting (which should be 300 dpi).  
B) You’ll have a set of choices for how you want to render the image as a bitmap. Choose “halftone.” 
C) You can now determine the shape, frequency and angle of the dots in the halftone matrix: 
1) For a traditional halftone pattern (like what you’d see in a newspaper photo), choose “ellipse” or “round,” but you can of course play with other shapes to see if there’s something you like better. Any shape will work in the screen printing process. 
2) Frequency is the number of lines of halftone dots per inch of image, expressed as “lpi” (lines per inch - compare to “dpi” [dots {pixels} per inch] in a regular image file). The higher the frequency, the finer and more “photographic” the halftone, and the greater the level of detail it can render; coarser halftones have a more stylized look (think Roy Liechtenstein, or classic comic books). 
Frequency also presents a technical issue, in that too fine a halftone can cause problems in too coarse a mesh. Generally speaking, the maximum lpi of your halftone should be 1/4 the thread count of your mesh – so, for example, if you’re using a 195 mesh, you don’t want to go much over 45 lpi. If you do use too fine a halftone, you will find that your screen ends up with a moiré pattern, a pattern of interference in the grey areas of the image not unlike what you might see in a kaleidoscope. Not the end of the world, of course, but best avoided unless it’s what you’re going for. So choose a frequency that you like, but without going over the limit of what your mesh can hold. 
3) Choose the angle of the lines of dots. This is totally up to you and has no technical bearing on the process. 22 and 45 degrees are both traditional, but play with different angles and see what takes your fancy. 
VII) Your picture will be magically transformed. Change the mode back to “grayscale.” 
VIII) If this is your whole image, you’re done. Huzzah! If it’s a part of a larger image: 
IX) Using the magic wand, highlight something black. Then hit “similar” and it will capture all the black dots. 
X) Cut-and-paste it back into your original document and position it however you want. 
Groovy. Your complex photographic image is now ready to shoot into a silkscreen. 
But first you have to print it out. The best way to do this is to get hold of some transparencies made for the type of printer you have (inkjet or laser) and print on them. To maximize opacity, you’ll want to experiment with different print settings (e.g. setting your printer to “photo” might make a more opaque print). I use an Epson printer set to “plain paper” and “best” print quality when I make my printouts, but figure out whatever works best for you – I think most printers are different when it comes to names and settings. 
Alternately, you can print your image on paper and take it to a photocopy place to have it copied onto a transparency. Most places stock them, and it’s definitely cheaper to do that than to buy a whole box of transparencies if you’re not sure how often you’ll be doing this. 
And if you can’t find any way to get your image onto a real film, you can print it out on paper and oil the back of it. That works – not brilliantly, but it works. Use it for not-very detailed images - I’d not attempt the oiled-paper thing on 12-point text or a 45-line halftone, for instance. 
2) Coat your screen 
Before you do any of this, you can (and probably should) degrease your screen. I usually don’t, but that’s no indication of the right way to do anything. Degreasing will get rid of any grease, dirt or other funk-type items that impair the emulsion’s adherence to the screen. So buy some degreaser and follow the instructions on the bottle. Or dissolve a drop of Palmolive or other dishwashing liquid (not dishWASHER liquid, mind you) in a big tank of water and wash your screen with it. Or be like me and don’t do anything. But don’t say I didn’t try to convince you. 
Get yourself some photo emulsion. I’ve tried a bunch of them and have had mixed luck; the ones I use, which are the only ones I can recommend personally, are Ulano TZ and Ulano PROCLAIM (available from a number of sources). These particular emulsions work for both water-based (which you’ll most likely be using) and plastisol inks – if you’re using solvent-based inks, you may need to find other products and experiment with them a bit. 
Photo emulsions are serious chemicals, and there are a fair number of different technologies used to make them, but emulsions like the ones above, which are most commonly available and probably most widely used, are called “diazo.” Don’t ask me the chemistry of them, I have no idea about it. But stick to diazo emulsions (and specifically the ones listed above) for the purpose of following these instructions.  
Diazo emulsions have to be sensitized before they can be used. Typically, a bucket of emulsion comes with a little bottle or jar of powder. Mix the powder with water according to the manufacturer’s instructions, stir it in and mix VERY thoroughly under low light. 
As a side note, many folks will tell you that the entire process of coating and exposing the screen needs to be done in darkroom/safelight conditions. I find that not to be the case – emulsion is light-sensitive (obviously) but not extremely so. Unless you’re mixing or coating your screens outdoors in the sun, you should be okay – I work under fluorescent lights and have never had a problem. 
Anyway, you really, really want a scoop coater for the next part of the process. A scoop coater is a little trough with a straight edge that you use to hold and spread the emulsion. Some DIY sources tell you just to use your squeegee, but that sounds to me like a recipe for frustration. You can buy a scoop coater for not very much cash at any one of the places listed at the end of this article. 
Prop your screen up the long way (i.e. “portrait”-wise), more or less straight, against a wall or other vertical surface. Pour some emulsion into your scoop coater and bring it up to the bottom of the screen. Tilt it forward until the emulsion in the coater is touching the screen. Then, pressing the edge of the coater firmly against the screen (but don’t go crazy with the firmness), bring the coater slowly up to the top. This should yield an even coat of emulsion across the entire screen. 
Then flip the screen and do the same thing to the other side.  
Now would probably be a good time to mention that screens have two sides (duh), and they’re called the squeegee side and the print side. If you think about the bars of the frame and the mesh forming a shallow 5-sided box, the squeegee side is the inside of the box, and the print side is the outside. Anyway, generally you coat the print side first, and then the squeegee side.  
At the end of the process, you want to have a thin, even coat of emulsion across the screen – the thicker it is, the more difficult it will be to shoot properly, and if it’s uneven, it will become a big headache quick.  
Once your screen looks beautiful, set it to dry in front of a fan. You do want total darkness for this step. If you don’t have a windowless room, block out the windows with whatever’s handy. The screen will be sitting there for a while, so even a little bit of light will have a chance to affect it. 
Wait about an hour (or up to 24 hours). Amuse yourself in whatever way you see fit. 
3) Shoot your screen 
You’re going to need a lighting setup of some kind to do this. Big shops use light tables that give a perfectly even, optimized blast of light over a large surface utilizing sophisticated lighting elements, vacuum hold-downs and all sorts of technological gewgaws. They can expose a screen in seconds. Unfortunately, they also take up a huge amount of room, and can cost as much as some cars. Suffice it to say I don’t use one in my work. 
Happily you can rig a perfectly good exposing setup yourself pretty quickly and cheaply. Your setup (and mine) consists of: 
A lighting FIXTURE (aka a lamp - I like the ones they sell at the hardware store, which consist of a socket on a cord with a metal reflector around it and maybe a clamp attached). 
A LIGHT BULB (I use a 500W photoflood bulb, available at well-stocked or old-school photo supply stores; you should too, especially if you’re following my instructions). 
Something to MOUNT the light on (for years I draped mine over the edge of a table and taped the cord to the table with duct tape). 
A piece of GLASS to hold the film down on the screen (some people just tape the film down, but I find that light has a way of getting under the film if it’s not weighted down). 
A piece of black CLOTH to go under the screen (it could be a sheet, or an old t-shirt if your screen isn’t crazy huge – improvise). 
A FLOOR (and you should already have one of those). 
A SINK with a sprayer, SHOWER or GARDEN HOSE (see above). 
Now, shooting a screen is probably the most variable-heavy part of the whole process. Different emulsions respond differently to any given light source, and any given emulsion responds differently to different intensities of light and different colors of light. You can change the intensity by using bulbs of different wattages and placing your light nearer to or further from your screen. You can change the color of the light by using different types of light bulb (e.g. incandescent, fluorescent, halogen, etc.). And, when you’re using a single light source (i.e. a bulb), the light will be more intense directly under the bulb than it will be off to the sides, since the center is closer to the source than the sides are. All in all, one must minimize variables to shoot screens successfully over and over again.  
The upshot is that I will give figures for how my setup works, but if yours is substantially different, you should make a test screen and see what exposure time works best for you. I’ll give instructions for that in the “***” section at the end of this part. 
So set up your lighting fixture, with the 500W photoflood bulb in it and the reflector mounted on it. Let’s say for the sake of argument that you’re draping it over the edge of a table; make sure there’s enough floor space under the edge for your screen to sit flat, directly underneath the light, and that the path of light from bulb to floor space is not blocked by something like a leg.  
I) Position your light so that the bulb is about 22 inches off the ground, pointing straight down. 
II) Spread your black cloth out on the floor.  
III) Put your screen on it, print side up (i.e. the mesh is on top of the screen).  
IV) Put your film on the screen, BACKWARDS (since you want it to read forwards from the squeegee side – embarrassingly, I have made this mistake a number of times and almost certainly will again). 
V) Put your glass over the film, so that it holds the film down on the screen – and make sure the edges of the glass are not touching any part of your design, since those edges mess with the light directly under them. 
VI) Turn on your light. 
VII) Let it sit for 15 minutes. 
VIII) Turn off your light. 
Now, when you take the film away, you should be able to see the image burned into the screen – black/unexposed areas of the image will generally be lighter than clear/exposed areas, since the light generally darkens the emulsion as it exposes.  
Wash out the screen – if you’re doing it outside with a garden hose, I’d advise doing it out of direct sunlight. At any rate, get both sides really wet, and spray, spray, spray (with your garden hose [probably not on full-blast], sink hose or shower nozzle). After about half a minute, you should start seeing the unexposed areas dissolve.  
Yay! Your screen is developing!  
You can gently rub the screen under the water to speed things along, but don’t be too vigorous - you could still rip up the emulsion with brute force, and that would be no good at all. Water pressure is best, since it shoots stuff out of the screen, rather than pushing it from side to side. 
In general, the finest details will be most recalcitrant.  
When you think everything has come out, hold your screen up to a light (or window, etc.) and look through it. The open areas should be completely clear. Any detail that the light doesn’t shine through is covered by a little skin of emulsion, and you need to keep working on it if you want it to come out.  
Finally, when there’s no more unexposed emulsion in the screen and you can see your design as a pattern of totally open and totally blocked areas in the mesh, set it to dry.  
Once it dries, take it out in the sunshine for a few minutes to let it “post-flash” – this will harden the emulsion and generally make the screen more durable. If it’s night time, or raining, you can just put it back under your light for a little while.  
Then, hold your screen up to the light to check for pinholes, which (as the name suggests) are little holes in otherwise blocked areas of the screen that are not part of your design. Cover them with tape, or paint over them with a little emulsion and let dry in the sun.  
Run strips of packing tape over the outside edges of the screen, where the mesh meets the frame. Then tape off the inside of the screen, again where the mesh meets the frame. The idea is to tape over all stray open areas of mesh (so not your design, obviously) and all crevices. This will prevent the ink going where you don’t want it to and save you a whole bunch of headaches. 
You’re done. Your screen is ready to print. 
*** To make a test screen, place a fairly detailed film on your screen and follow the instructions for exposing, but use a black cloth or other opaque covering to expose your image bit by bit in, say, 10 increments – i.e. start with just a sliver of the screen uncovered, then after however long, move the covering back an inch or two, and repeat until the whole screen is uncovered. Then let it sit for however long your “minimum” exposure time is – since nothing you’ll be using is likely to take less than about 10 minutes to expose your screen. 
For a 500W bulb, I’d make increments of 1 minute each from 10-20 minutes (so that the least exposed part of your screen will have been shot for 10 minutes, and the most exposed part will have been shot for 20). For a 250W bulb, I’d make 3-minute increments from 20-50 minutes.*** 
So you have your screen and your stencil (and for those of you not using photo emulsion, welcome back). Now you want to print! As well you should. What’s the point of making a silkscreen if you’re not going to make a print with it? 
First you have to decide what you’ll be printing on, and then what type of ink you’ll be using. For right now, I’ll assume you’re printing on t-shirts, or textiles of some kind, since that’s as good a place to start as any, but I’ll get to paper in the next section. 
Ink is the real question. You essentially have three ink options for printing on textiles. They are: 
A) Water-based (which nearly everyone starts out with) – a water-soluble medium full of dyes and/or pigments, and roughly the consistency of pudding. Printing with water-based ink requires very little special equipment but is a bit tricky to get the hang of. Water-based inks are great at printing dark colors on light fabrics, less so for printing light colors on dark fabrics – they have a slight problem with opacity.  
B) Plastisol (which is used for most “conventional” t-shirts) – a solvent-soluble medium roughly the consistency of cream cheese. Printing with plastisol inks requires some specialized equipment, but is much less tricky than using water-based inks. Plastisol inks are very well behaved, and are equally useful for printing light-on-dark or dark-on-light. 
C) Discharge (which is considered a specialty ink) – a water-soluble medium full of pigments and bleaching agents, again roughly the consistency of pudding. Printing with discharge inks both requires special equipment and is tricky as all get-out. But the results are wicked, wicked awesome. Discharge inks are used pretty much exclusively to print light or highly contrasting colors on dark or bright fabrics. 
Chances are you’ll be starting with water-based inks, so that’s where we’ll start too. 
It’s interesting that the first print technology everyone learns is one of the most difficult.  
Go to any punk rock show and check out the t-shirts that the guys in the bands have made themselves. Chances are they’ll have off-center graphics with an uneven thickness of ink, maybe a patchy area where the ink has clearly started to clog the screen, maybe thumbprints or spots from stray ink drops – that’s the face of water-based screen printing, and it’s what everyone goes through. 
Water-based ink is a pain in the rear because a) it’s runny, and b) it dries in the screen. But it’s also the only ink you can really use without specialized equipment and chemicals, so it’s where we all start.  
Water-based inks are also best used to print dark colors on light fabrics – think of them essentially as dyes. They do make opaque water-based inks, but they are tricky to use (they dry much more aggressively in the screen) and never really fully block out the color of the fabric. However, if you want to print light-on-dark, go ahead and give ‘em a try. 
(Side note: back in the day when I was just learning how to print [in the mid-90s] there was a series of inks called “Texilac” that were both water-based and super opaque. They had a thick, paste-like consistency, dried much more slowly than conventional water-based preparations, and printed beautifully and permanently [one of the shirts I made back then is still being worn, and washed, 14 years later]. They were awesome; and then the one company that distributed them in the US [they were made in Italy] closed down, and you can’t get them here any more. Fie!) 
Enough chatter; get your screen. It’s printin’ time! 
Preparation is the name of the game in order to avoid the above-mentioned hazards and a generally stressful printing experience. I never thought I would say this, and my mother would be shocked to hear it, but the only way to make water-based printing work is to WORK CLEAN. 
You will need: 
A BOARD for the  
T-SHIRTS, which are in a pile at this point 
ADHESIVE of some kind for the board – ideally spray adhesive from a screen shop, but a light, dried coating of rubber cement might work 
A place to dry the shirts; or, better yet, a CLOTHESLINE 
Propylene glycol or other substance to act as a RETARDER (more on this in a sec) 
A disposable CUP or bowl 
Something to make test prints on – ideally PELLONS (also called test squares, which are big squares of thin felt-like fabric available from screen supply stores) or old t-shirts, but newsprint or blank paper will do in a pinch 
PAPER TOWELS for reasons that should be obvious 
NEWSPAPER to cover your work area, plus another stack to replace the sheets you will invariably spill ink on 
A roll of PACKING TAPE to rest your squeegee on (why a roll of packing tape? Why not?) 
And realistically… another PERSON to help you. At least the first time you do it. 
You want to have this collection of objects well organized and within arm’s reach, or at least as close as possible – a chef would call it a “mise en place.” The reason to keep everything close is that you (and the chef) will be working under time pressure. If he (or she) takes too long to do something, food will burn; if you take too long, your ink will dry. 
Okay – first things first – the squeegee. NOT the squeegee you wash windows with. At all. It’s a totally different piece of equipment, albeit with the same name and a similar function. A good screen printing squeegee has a sturdy wooden handle and a firm, sharp-edged rubber blade at least a quarter of an inch thick.  
Many hobby and art supply shops stock tiny squeegees with floppy blades and/or narrow plastic handles, which are no good at all. It always bewilders me why, when selling to people who are inexperienced or just learning the process, these companies decide to provide chintzy versions of items that are ten times harder to work with than the real thing – and naturally cost just as much.  
The squeegee is your most important tool apart from your screen. Buy a real one online or from a screen shop. They aren’t expensive, and they’re much easier to use than the hobbyist models. Get one that’s at least two inches wider than your design, but not wildly more than that. 
The shirt board can be any flat board that you can stick a shirt over – I used to use a piece of half-inch thick particle board cut out to about 18”x24”. Flat is the name of the game. If the edges are rough, seal them off with some packing tape, which will allow the shirt to go on and off much more smoothly.  
If you don’t have a clothesline set up someplace near your workstation, you can clear off a section of floor to put the shirts on to dry. They take about 10-15 minutes to dry to the touch, so factor that into your plans. 
The ink is the next key component. You’re likely to find Speedball textile inks much more readily than other brands. I’ve had mixed results with them, but they’re pretty much fine to start with, and they’re the standard as far as non-industrial water-based textile inks are concerned. Pick a color you like. Or mix one if you’re feeling frisky. 
Next thing is retarder. Retarder is a substance you mix into the ink to slow the drying process. Drying in the screen is your mortal enemy; anything that slows it down is your friend. I usually use straight propylene glycol, but that can be hard to find. Speedball makes a retarder which you can use if you find it. Or you can use lube. “Personal lubricant,” if you will. Main ingredient of most mainstream brands: propylene glycol. Fun fact. 
Measure out about half a cup of ink for every ten or so shirts, just to get started. Then mix it up with 5-10% of its volume of retarder in your cup. 
Now get your workspace and your “mise” ready. Clear off an area of table (or floor, in a pinch) at least three feet by three feet. Cover it with newspaper. Put your roll of tape towards the side. Put your roll of paper towels where you can easily get at them.  
Spray or spread your adhesive on the board – lightly. It needs to be tacky, in order to hold the shirt down when you pull the screen up and off, but it doesn’t have to be sticky, and in fact shouldn’t be, lest it become a nightmare to remove shirts from the board. (Side note – I haven’t used rubber cement for this so can’t vouch for it, but it may work – in any case, let it dry completely before putting a shirt on it, or you’ll have problems. 
Put a t-shirt over your shirt board, as though the board was wearing the shirt. Get it on straight, so that if your design is straight in relation to the board, it prints straight on the shirt. Then practice pulling it off. See if you can do it without letting one part of the fabric touch another, since you’ll be taking shirts with wet ink off the board and needing to preserve the print while doing so. 
Put whatever you’re test-printing onto on the board (e.g. a pellon, an old shirt, or a piece of newsprint). You are ready to pull your first print. But READ THROUGH THE REST OF THE INSTRUCTIONS BEFORE STARTING. That’s just common sense. 
I) Lay the board down in the middle of your work area.  
II) Have your assistant hold the screen parallel with the floor. Pour a line of ink about an inch wide just below the bottom edge of the design.  
III) Place your squeegee just below the line of ink. Using very light pressure (imagine you’re spreading icing on a cake), drag a very thin layer of ink across your entire design. This is called “flooding” and is used to prevent ink from drying into the screen. 
IV) Place your screen firmly on your shirt, so that the design is going to land where you want it to on the shirt. Once it’s down, don’t move it – you will have a giant inky mess all over your shirt if you do. Getting your design centered may take a few tries to get right, but once the screen touches the shirt, consider it committed. 
V) Have your assistant hold the screen tightly on the shirt. 
VI) Hold the squeegee at about a 60 degree angle (i.e. more upright than not, but not perpendicular) with the screen, pointing away from you and down. Applying firm (but not hard) pressure, drag the ink across the screen. 
VII) Pull the screen up off the shirt. You should see a print on your shirt. 
VIII) VERY IMPORTANT – use the squeegee to flood (drag a thin layer of ink across) the screen again. Always leave your screen flooded when it’s at rest. Failure to do so will clog it up faster than you would believe. 
IX) Prop your screen up somewhere where the mesh won’t be touching anything. Rest your squeegee on the roll of tape, so the blade isn’t touching anything.  
X) Carefully take the shirt off the board; have your assistant go hang it up or put it on the floor. 
XI) Put another shirt on the board and repeat steps IV through X. 
You just made a shirt. Assuming you want to be able to wear it, you’re going to want to also wash it at some point. To ensure the ink stays in the shirt through multiple washes, take all of your shirts (when they are TOTALLY DRY), go to a laundromat and tumble them in a commercial dryer on “high” for 45 minutes. The heat should permanently set the ink. 
Now, some common problems: 
Ink will go everywhere. Use diligence to make sure that you wipe up or otherwise deal with any spills before they get on shirts and ruin them. If ink puddles or smudges on the shirt, it’s likely to have smeared on the screen too. Wipe the back of the screen gently with a paper towel before making another print. 
Ink may also dry in the screen. Your best defense is to keep it flooded whenever you’re not actually printing, and work as fast as you reasonably can without getting sloppy, but it will still dry on you at some point, in all likelihood. Be on the lookout especially for fine details disappearing. If your screen does start to clog, my advice is to wash it out as quickly as you can – dried ink can be permanent if you don’t take care of it promptly. 
Squeegee technique is a muscle-memory thing, and it’s really something you only learn by practice. Expect to have more luck the more prints you make. A helpful way to understand it is that the squeegee essentially performs two jobs – pushing ink through the screen, and scraping away the ink on top of the screen. You modify these two functions mostly with the angle of your squeegee – a more acute angle to the screen forces more ink through, whereas a more obtuse angle cuts more ink off. Ideally, you want to push enough ink through to make a bold design, but cut enough off to preserve detail. Experiment and you shall be rewarded with better and better prints. 
But say you don’t want to print t-shirts. You want to print posters, or better still, fine art. You need to modify the process a little bit. 
The process of printing on paper (or glass, or metal, or plastic, or wood, or anything flat – in general, “graphic” printing) is in many ways the same as the process of printing on t-shirts. But there are, of course, a few notable differences.  
The first is that you have a massive choice of things to print on. And within the variety of substrates, there are both great opportunities and new and unique challenges. You’re not constrained in terms of size, shape or texture, but you will have to figure out strategies to deal with whatever you print on.  
Another is that you no longer have to focus on what will survive the wash in terms of inks, so a whole world of different media opens up to you. You can print opaque colors or transparent ones. You can print with glue, lacquer, house paint, intaglio ground, or anything that you can think of that will go through a screen.  
Last for now, and most importantly, you can now fairly easily print multiple layers of color. This brings with it the question of registration, or how to make one layer line up properly with another.  
First things first: making a one-color screen print on paper. 
Your printing setup will be fairly similar to the one you used to print shirts, but with a few extra items. 
To wit: 
HINGE CLAMPS, which are remarkably what they sound like – clamps with little hinges welded to them. These allow you to affix your screen to a surface and raise or lower the screen. They are indispensable and available fairly cheaply from art supply or screen printing shops. 
A TABLE that you can drill some holes in without upsetting anyone; or, if you don’t have that, a flat BOARD big enough to support your entire screen, and again that you don’t mind drilling holes into. 
A BLOCK of some kind to rest the screen in the “up” position – it could be a block of wood, an ink can, another roll of packing tape, or whatever will hold the screen up. 
And EVERYTHING LISTED ABOVE in the textile printing section, substituting newsprint for the fabric test squares or old t-shirts that you were making your test prints on. 
To build the actual setup, you want to drill holes in the table or board a few inches narrower than the short side of your screen. Then simply screw your hinge clamps down, and you have a pretty good working system. (There is also the added bonus that you no longer really need an assistant to hold the screen or help you move things out of the way. You can rest the screen on the block and do everything yourself if so inclined.) 
Prepare your “mise” again – gather up all your supplies and have them at hand. Stack your paper (or whatever it is you’ll be printing on) near your setup, but not so near that you’re likely to spill ink all over it. Also, and this is even more important than it was in t-shirt printing, have at hand a big stack of newsprint. Bigger than you think you’ll need. And flat (so don’t just use an unfolded newspaper). Printing errors are far more common on paper for some reason, and you will definitely want surfaces you can print on and toss away to preserve the good paper for your edition. 
Mix up some ink with retarder. Pay attention to how big and open your design is. If it’s going to use a lot of ink (i.e. it has lots of wide open spaces, or it’s just plain huge), mixc more ink than you think you’ll need. You can always save it in a clean jar, yogurt container, lidded bowl, etc. 
Now, we print. 
I) Attach your screen to the hinge clamps by sliding a short edge into the clamps and clamping it down. It should now swing up and down like the hood of a car. 
II) WITHOUT PUTTING ANY INK DOWN, slide a piece of your paper under the screen.  
III) Looking through the screen, position the paper underneath the design so that it is centered how you want it. Mark the corners of the paper on the board or table using marker or masking tape. Assuming that all your paper is the same size, this lets you know where to put the paper in order to have each print come out positioned correctly.  
IV) Replace your good paper with a piece of newsprint. 
V) Raise the screen, put a line of ink below the image (exactly as you did when printing shirts) and lay your block under one edge of the frame. Rest the screen on the block. 
VI) Take your squeegee and flood (lightly coat) the ink over your design. 
VII) Remove the block and lower your screen.  
VIII) Using firm (but not crazy) pressure, make a print. 
IX) Raise the screen, flood the screen, replace the block and remove your paper.  
X) Hang it on the clothesline or put it on a clean surface to dry. 
XI) Put another piece of paper in and repeat steps V-X.  
You definitely want to make your first print on newsprint, and keep printing on newsprint until the image is coming out the way you want. If, during your print run, you start to see errors (drips, clogs, ink going every which way), just switch back to newsprint until the errors are corrected, then resume printing on nice paper. 
So now you have single-color paper prints, which is fantastic. But the real power of graphic screen printing lies in your ability to make prints using as many colors as you like. In order to do this, there are two new steps. 
The first, obviously, is that you need a separate screen for each layer (or, to look at it another way, each color) in your final design. Essentially, this means that before you start making any screens, you should know where you want each color to fall. Each color will be made into a film, and each film will be made into a screen. 
There are a few ways you can work this out.  
Say, for example, that you have a drawing of a house on grass with a sky behind it. You want the lines of the drawing to be black, the house to be red, the grass to be green and the sky to be blue – a four-color print. In this example, the drawing acts as a “key” screen – it determines where all the rest of the colors go.  
One way to make screens for the other colors would be to print out your key film and trace the areas you want to be other colors onto new films, fill them in and use those films to shoot screens. 
But the more rigorous (and far more versatile) way to do it would be to make a color separation in Photoshop. Here’s how: 
I) Get your “key” drawing into a Photoshop file (by scanning, creating it within the program, importing from outside or whatever). Prepare it as for line art above. 
II) Using the Magic Wand tool, highlight (marquee) all the areas within the drawing that you want to be color number one.  
III) Make a new layer by clicking on the “layer” tab on the top menu bar. 
IV) Making sure the color in the tool bar is set to black, use the paint can to fill in the highlighted areas on the new layer. 
V) Repeat steps II-IV for each color you want to make. 
Presto! Now each layer represents a print color. You can print them out separately, and make screens according to the instructions above. 
Okay, now say that you don’t have a key screen – in this example, you have a green, red and blue image that you want to divide up into green, red and blue screens. You can use a modified version of the above process: 
I) Open your file. 
II) Highlight something red with the Magic Wand. 
III) Right-click on it (or whatever the Mac equivalent is, if you’re using a Mac). Select “Similar” from the drop-down menu. All red areas should now be highlighted. 
IV) Make a new layer as above. 
V) Fill it in black with the paint can. 
VI) Repeat II-V for green and blue. 
Of course, the major flaw in this process is that it doesn’t allow you to make a color separation from a shaded image. For instance, say instead of a simple red, green and blue design, you have two or three different shades of red in the original image. You want them to all be printed as one red layer in the final process, but using the “Similar” command won’t highlight them.  
In that case, I’d say make a separate black fill-in layer for each shade according to the instructions above, then link the layers in the layer menu and merge them by clicking on “Layer” and “Merge Linked”. You should now have one layer that works for you. 
So now you have separate films, and you’ve made them into separate screens. How do you print them so that all the colors line up? Glad you asked. 
Your setup is the exact same as last time (when you made your single-color print on paper) with a couple of additional items: 
A thin, flexible plastic TRANSPARENCY a few inches larger than your paper on all sides. Traditionally we call it “mylar” or “acetate” but it can be made out of any plastic that will take ink. 
A magic MARKER 
You will use the transparency and tape to show you where the image on your screen is while you print, which will let you line up your paper properly so that the colors each fall where they are supposed to. 
Good. Assemble your mise. Mix your ink. Get ready to print! 
Let’s assume, for the sake of the instructions below, that you’ve already printed the first color of your edition according to the instructions above. Pile up those papers, alongside some clean newsprint and maybe some of the newsprint you printed on in the first run (i.e. which already has the first color on it – not essential but helpful). 
I) Put your screen into the hinge clamps and clamp it in. 
II) Take your transparency and put it under your screen, more or less centered.  
III) Tape down the transparency on one edge. Some folks like to use the left edge, some the right, and some the one closest to themselves. The only edge not to use is the back edge (i.e. the one near the hinge clamps).  
IV) Flip the transparency back and reinforce the tape on the other side of the same edge – you’re essentially making a hinge, so that the edge is taped on both sides and is unlikely to move. 
V) Put the transparency back into the flat position, and put a piece of masking tape on the edge opposite to the hinge. Tape the transparency down to the table. 
VI) Using your marker, draw a line on the print surface (your table or board) across the masking tape. Essentially, you now have a guide that tells you where the transparency is supposed to fall. Leave the transparency down. 
VII) Ink and flood your screen, as above. 
VIII) Make a print onto the transparency. Pull up the screen and flood again. 
IX) Pull back the transparency. Put a piece of your paper (with the first color already printed) onto the board.  
X) Using the transparency as a guide, position the paper so that the ink will fall in the right place. Put down the masking tape to check that the transparency hasn’t moved (and thus become an unreliable guide) – if the line goes straight across from the surface to the tape and back to the surface, it’s exactly where it was when you printed the transparency. 
XI) Once you get it registered, pull back the transparency, drop your screen down and pull a print onto your paper. The ink should fall exactly as it did on the transparency.  
XII) Pull up the screen, rest it on the block, FLOOD IT, put the paper someplace to dry and repeat steps IX-XI for the rest of your edition. 
And that’s it. Repeat for every color in your design.