DIY screenprinting can be as easy or as complicated as you want it to be. Here's how I do rainbow screenprints!
What You Will Need:
Frame (either purchased or DIY – the frame I used here was from THIS Instructable)
Screenprinting mesh (see below for links to info on which type of screen mesh to get)
Squeegee (ditto! Keep reading!)
Drawing fluid and screen filler
tablecloth, wax paper, or other surface protector
Super Washing Soda (I use Arm and Hammer)
screenprinting ink (be sure to pick the appropriate type for your substrate. Fabric, paper, etc – yes, it makes a difference!)
Optional (but recommended):
gloves (because it can get messy)
scrubby thing (dishwashing brush or something of that nature)
Frame: there are pros and cons as to which type of frame to use; I'll leave it up to you to decide which option would be best for you. In my case, given that I planned to do limited runs of a small number of projects, it was faster and more cost-effective for me to build my own frames using this Instructable. There are other ways, but this one has worked for me so far. A larger scale operation would probably benefit from store-bought frames or screenprinting systems.
Mesh: it does make a difference as to what type you get. See here for an expanded explanation of mesh types, sizes, and uses. The following links will help you understand those weird numbers and letters and identify which type you might prefer for your particular project. ( Screen Mesh Conversions, Screen Mesh Tips and Tricks, and Screen Mesh Suggestions)
Drawing Fluid and Screen Filler: there are a number of ways to create the template for your screenprint, including photosensitive films and the like. This method is a bit messy, but you don't have to worry about exposure times and it's worked out cheaper for me – again, in small runs. I'm using Speedball brand filler and fluid; my bottle of drawing fluid is still quite full whereas this is my third bottle of screen filler. You'll go through more filler than drawing fluid, so keep that in mind. Addendum: The Super Washing Soda was recommended as an additive to help wash the screen filler off the mesh, and it does seem to help. One box will go a long way as well.
Squeegee: you will use this to pull your ink down across your design. You want a squeegee that is large enough for your intended use (too small and you'll ooze ink off the sides and you really want to avoid doing multiple passes unless it's part of your intended design). They have different durometers (hardness) – the higher the number, the less it flexes. There are different sizes and materials – there's a more in depth rundown here.
Contact paper: used to protect your design. I like to print out the design then cover it in contact paper before I lay the frame over it. No matter how many shims I use, I almost always seem to get some drawing fluid on the pattern, so it's nice to protect it especially if you think you might reuse it later on.
Tablecloth: to protect your surface, especially during the screen filler stage. Better safe than sorry. This is just a dollar-store plastic tablecloth.
Spatula: Used mainly to get ink out of your pots (and back in, if you are going to reclaim ink).
Popsicle sticks: stir inks if needed, especially if you custom mix a color. I also use these to build shims to keep the frame up off the surface during the push stage. (Tip: Build a stack of popsicle sticks to the height that you need, then wrap tape around it to keep them in a stack. Trust me, you don't want these moving while you're screwing around with the frame.)
Iron: this is used to heat set your paint/ink depending on the brand, type, et cetera. Some inks say you just need to air dry, others suggest using a dryer (might be good if you're doing a bunch of shirts I suppose) or other commercial flash-drying solution. But for the at-home DIYer, an iron's probably the most efficient option you'll have.
Step 1: Assemble Your Frame
Assemble your frame. Whether you made or purchased it, you need to attach the mesh somehow. You want to make sure the mesh is as TIGHT as you can get it, since saggy mesh will screw up your print. If you're using a store-bought frame, follow the instructions. For this DIY frame, I used staples to attach the mesh to the frame. BTW, this is a pain in the butt when you need to replace the mesh -- it does wear out -- so keep that in mind.
Step 2: Prepare Your Design
If you are planning to print a variety of sizes of your design, either prepare different sizes of the same design or choose a median size. I tend to create my design on the computer, size it appropriately, and print it out. Others can freehand draw it or... whatever! :)
The important thing to keep in mind is that when you trace over it on the mesh with the drawing fluid, whatever you paint will remain clear – i.e. it will be inked. For example, in my picture below, all of the WHITE space will be painted over with drawing fluid. You can do a negative image, or any way you like as long as you remember how the drawing fluid works.
I cover my designs with contact paper for protection, because I always seem to get drawing fluid on it anyway. This is bad, not only for your design if you want to reuse it, but for your screen because it might mean the drawing fluid doesn't fully cover the mesh and might leave holes for your screen filler to sneak into. So contact paper and shims are important!
Step 3: Layout and Drawing Fluid
Lay your design on a flat surface and place your frame over it. Make sure your frame is large enough to accommodate the design as well as some extra room. You want to lay it print side down – as in, the surface that will contact your paper or fabric should be touching your design. Once your frame is centered, elevate it with shims to prevent the mesh from touching the design as you paint. Begin to paint over your clear areas – the areas that you want ink to show – with the drawing fluid. You don't need to put down a super thick coat, but you want to make darn sure you have good coverage. When you're done, leave it horizontal and allow it to dry for a while. (It dries faster in a warm place and/or with a fan over it for circulation, but I've never had it take longer than a couple hours.) Pick up your frame and hold it up to a light source to check for holes or thin areas. Go back over these with more fluid if there are any.
Oh, and now would be a good time to put a tablecloth down if you haven't already.
Step 4: Screen Filler
Once your fluid is dry, hold the frame at an angle to your work surface. Working on the SAME SIDE that you painted the drawing fluid on, pour the screen filler down from top to bottom. You may want to use the squeegee to help push – but you don't want to go over the same areas a lot. Ideally you want just one or two passes. It's better to add too much filler than too little – you want to make absolutely sure you cover your entire design area plus a fair bit on either side, since you don't want ink bleeding through around the edges… unless it's part of your design! With my frame, I've been able to kind of pour extra filler back into the bottle by dipping the corner into the bottle and letting it run off into there. It's probably not recommended, but hey, we're all rebels. In either case, lay your frame back down to dry horizontally. (Again, NOT touching any surfaces! Shims. Shims, my friend.) This stuff also dries fairly quickly, but make sure it's dry before you go messing with it. You should light-check it again – I've used a paintbrush to fill in any really thin spots.
Step 5: Washout
Once your screen filler is dry, haul the frame to your shower or outside to your garden hose or something. Rinse down the screen – same side as the one you painted the drawing fluid on. Warmer water will work faster. I also spray the back side down a bit just to be safe. Ideally the areas that you painted over with drawing fluid will wash out, leaving just the red screen filler. If it's being particularly stubborn, you can rub it gently with your fingers or a stiff bristled brush (old toothbrush works pretty good for this). If all goes well, you should have a decent image of your design. Allow it to dry for a while.
Note to self: Clean the garage shower. Ew.
Step 6: Layout. Again.
When your frame is all dry, lay out your print surface. If it's a shirt, make sure it's washed and dried (and de-furred if you have cats like I do...) and preferably stretched a bit over some sort of protected supportive surface – I like to use cardboard wrapped with wax paper. The support helps keep the fabric stretched taut for a crisper image, plus prevents bleed-through to the other side of your shirt. Line up your frame over the print area. I like to use bits of tape to help keep the frame aligned, etc. You also can use the tape to cover any areas on your frame that were not covered by screen filler.
Use shims to lift the frame off the print surface once it's aligned. You don't want the mesh to touch the fabric at this point. I've seen people say 1/16'' to 1/8'' off the surface... your mileage may vary and depends on how much pressure you tend to use during the push stage. If this is a particularly IMPORTANT project -- do test runs first to figure out shim height, pressure, angle, and all that fun jazz.
Step 7: Ink
Lay out your inks. If you were doing single color, you would lay out a nice row across the top (or side) of your design. In this case I'm doing multiple colors, so I put several blobs side by side in a long row. The size of your blobs will dictate how thick of a stripe you get, as well as overlapping. Be sure you leave room on either end for “overflow” because the ink will flow down and out to the sides as you pull it down the screen.
If you want to promote blending of colors, put your ink at the very top of the screen and pull further before it hits the design to give the inks more time to play with each other. (You can see this happening in the narrow band of light green between the yellow/blue inks in the later pictures.)
Step 8: Pull!
Pull your ink. Set the squeegee behind your ink at an angle (about 45 degrees is what I've seen recommended but it depends on a lot of factors… your strength, your speed, thickness of the ink, etc) and pull downward from top to bottom of the frame, toward you. Use both hands, and try to keep your pressure and speed even. The pressure will cause the mesh to dip down to touch the surface and deposit the ink as you force it through – offset printing like this tends to produce a crisper image. When you have reached the bottom and your design is covered, lift the squeegee. Grasp your frame and lift it straight up in one smooth, quick motion.
Note: I know I only have one hand on the squeegee in the picture, but I had no assistant to take the picture. You can actually see in the finished photo where I stopped to take the picture due to this... and I would have had a crisper, more complete picture if I'd used both hands. So keep this in mind!
Step 9: Post-Print Cleanup
Step nine: While you wait for your printed image to dry, reclaim any ink that you might wish to (spatula or popsticle sticks work for this). Then take your screen and squeegee back to your washing area and gently wash off the ink with lukewarm water.
Step 9.5: if you have areas of missing ink, you can touch up those areas with a paintbrush or leave it as-is. (I might go back to touch up what's missing on this shirt at a later date.. but I kinda like it right now.)
Step ten: Set your ink according to manufacturer's instructions. For my inks, this calls for ironing on the reverse side once the ink's dry. Other inks might simply call for air drying, etc.
Step 10: Reclaiming the Screen
When you know you're done with your design and you're ready to reclaim your screen, take your screen to your washing area. Fill a bucket with some hot water, as hot as you can stand it, and a good amount of washing soda. Once it's dissolved, pour a bit of your water down your screen (same side as the filler was poured on) let it sit a little bit, then use a sprayer to help dislodge the filler. A scrubbing brush like you use for dishes can be helpful here. Sometimes doing a rinse and scrub on the backside can help clear the holes on the mesh. The longer the filler has been sitting on the screen, the harder it will be to remove it. I once left a design on my mesh for a year, and it did come out, but took considerably more effort than when the filler was only a day or two old.
I didn't get a photo for this step because it's pretty self explanatory and would be just as illustrative as the pictures of the washout stage (i.e. not very :) )