Make a screen from scratch, the cheap way

You need: a screen (buy one or build one, see Build a frame), a photo emulsion kit (a Speedball starter kit with Diazo emulsion and sensitizer works), plain copy paper, cooking or baby oil, a piece of glass or clear plastic, something black and flat (cardboard or a black shirt), tape, and a sunny day.

1. Print your layer. Save your files here, print layer A on regular copy paper as dark as your printer goes. A laser printer gives the darkest black. Print at 100%, no scaling.
2. Make the paper see-through. Brush or rub a thin coat of cooking oil or baby oil on the back. Let it soak in, then wipe off the extra so it is not dripping. Hold it up to a window: white parts should glow, black parts should block the light.
3. Clean the screen. Scrub the mesh with dish soap (no lotion kind) and rinse. Grease and dust make holes in your stencil. Let it dry.
4. Mix and coat, in dim light. Mix the sensitizer into the emulsion like the jar says (wear gloves). Turn off bright lights, a yellow bug light is safe. Pour a line of emulsion on the screen and pull it across with a squeegee or a stiff card, a thin even coat on both sides.
5. Dry it in the dark. Lay it flat, outside of the screen facing down, in a dark closet or a box. A fan helps. Wait until it is fully dry, a few hours to overnight.
6. Set it up. Black flat thing on the bottom, then the screen with the flat (shirt) side up, then your oiled print, then the glass on top to press it flat. The print goes on backwards (mirror image) on this side, so it reads the right way when you look through from the inside.
7. Sun. Carry it out covered with a towel, uncover in direct midday sun. Printers report about 25 to 60 seconds. Oiled paper blocks more light than film, so you may need longer. Do a test strip the first time: cover parts of a scrap screen with cardboard and uncover a strip every 15 seconds.
8. Wash it out. Cover it again, go inside, and spray both sides with cool water. Where your art was black, the emulsion washes away and leaves open mesh. Spray gently until the image is clean and sharp.
9. Dry it. Let it dry, then set it in the sun again for a few minutes to harden it. Hold it to the light: the art should be open mesh, everything else solid.

Washed out completely? Not enough sun. Art will not wash out? Too much sun, or the paper was not dark enough or the glass was not tight.

Build your own frame (and go big)

You need: 2x2 wood, wood glue, screws or metal corner brackets, a staple gun with 3/8 in or 1/2 in staples, screen mesh, waterproof sealer (spar urethane or outdoor polyurethane), duct tape, sandpaper.

1. Pick the size. The inside of the frame should be about 3 to 4 inches bigger than your art on every side. That gives the squeegee room and a place to pour ink. A 10 x 12 in design wants about an 18 x 20 in inside.
2. Cut and join the corners. Glue every corner and add 2 screws or a metal corner bracket. Staples alone will not hold the corners, the mesh pulls hard.
3. Sand and seal. Sand the edge the mesh sits on so nothing snags. Paint the wood with waterproof sealer and let it dry fully. Screens get wet every time you wash them, raw wood swells and warps.
4. Staple the mesh. Cut the mesh 2 to 3 inches bigger than the frame. Staple the middle of one side. Pull the opposite side tight and staple its middle. Do the same for the other two sides. Then work out from the middles to the corners, alternating sides, a staple about every inch, pulling as you go. Tight like a drum.
5. Seal the edges. Trim the extra mesh, then cover the staples and the wood edge with duct tape inside and out so ink and water stay out.

Super glue? You can skip it. Staples plus tape hold fine. If you want extra hold, run a bead of waterproof glue along the staple line, never on the area you print through.

Oversized custom screens (all over prints, posters, banners)

• Thicker wood. Past about 20 x 24 in, step up to 2x3 or 2x4 so the frame does not bow when the mesh is tight. Add a small corner brace (a triangle of plywood) at each corner.
• More tension. Big mesh sags. Stretch slower, go around twice, and re-tighten any loose side before stapling it down.
• Light that covers it all. The sun is the best light for a big screen. Use glass big enough to press the whole print flat, or two pieces butted together.
• The squeegee. 1 to 2 inches wider than your art, about an inch narrower than the inside of the frame. Big pulls go better with two people or a long squeegee.
• Big prints from small paper. Print your layer in tiles, line the tiles up on a window, and tape them together with clear tape before you oil them.

What mesh count means

Mesh count is how many threads per inch. Low number = big holes, lots of ink goes through. High number = tiny holes, thin ink, fine detail.

Halftones rule of thumb: mesh count about 4 to 5 times your dots per inch (LPI). 45 LPI wants about 180 to 230 mesh. Too low a mesh and small dots fall through the holes.

Do not know your mesh? Look at the edge of the roll or the bag. If it says something like 110 or 43T, the first is threads per inch, the second is threads per centimeter (43T is about 110).

Pull a print

1. Tape it off. Tape the inside edges where the mesh meets the wood, and cover any pinholes in the emulsion with tape or a dab of emulsion.
2. Flat and steady. Shirt on a flat, hard surface with cardboard inside so ink does not soak through. Tape the shirt down or use a board.
3. A little gap. Set the screen on top, flat side down. A coin under each corner lifts it a hair off the shirt so it snaps back after the squeegee passes. Cleaner prints.
4. Flood. Pour a line of ink above the art. With light pressure, push the ink across the art to fill the mesh.
5. Pull. Lean the squeegee about 45 to 75 degrees toward you, press firm and even, and pull it across in one smooth stroke. One or two passes, not ten.
6. Lift and check. Lift the screen straight up. Patchy? Flood again and pull again before moving the shirt.
7. Next layer. Let layer A dry to the touch. Put screen B down, line up its registration marks with the marks on A (tape a clear sheet with A printed on it to the board to aim), then print.
8. Set the ink. Heat set it the way your ink says. Speedball fabric ink sets with a hot iron or a heat press. Wash the screen right away, before ink dries in the mesh.

How CMYK works

CMYK is four see-through inks: Cyan (blue), Magenta (pink), Yellow and Black. Printed on top of each other in tiny dots, they make almost any color. It is how magazines print photos.

• Dots, not mixing. You never mix the inks in a cup. Each color is a screen full of dots. Big dots = a lot of that color, small dots = a little. Your eye mixes them from a distance.
• Overlaps make new colors. Yellow over magenta looks red. Cyan over yellow looks green. All three looks dark brown, so black gets its own screen for clean darks.
• Different angles. Each color's dots are turned to a different angle (cyan 15, magenta 75, yellow 0, black 45). If they all lined up you would get a wavy pattern called moire. This tool sets the angles for you.
• Needs a white base. The inks are see-through, so they need a white or very light shirt or paper. On a dark shirt you print a white layer first.
• Print order. Light to dark is a good start: A yellow, B magenta, C cyan, D black. The files here are lettered in that order.
• Registration matters. If a screen is off by a hair, colors look blurry. Use the registration marks and a fine mesh (230 to 305).

Easier first project: one color halftone on a shirt, or two colors. CMYK is the expert level. Get one screen right, then stack more.

Draw it right before you bring it here

The cleanest stencils start as clean drawings. Black marker, white paper, bold and simple.

• Full shapes, no open lines. Every shape should be a closed, filled area. A thin outline becomes a thin cut that tears or fills in. Fill your shapes in solid.
• Filled = cut out. Empty = what holds it together. Think of the parts you color in as the holes the paint goes through. The white around them is the sheet that keeps it all in one piece.
• Watch for islands. The middle of an O, A, B, D, P, R floats loose when you cut it and falls out. Leave a small gap, called a bridge, that ties it to the rest.
• Thick enough to cut. Keep lines and bridges at least about 1/8 in wide for paper and cardboard, a little thinner works for vinyl.
• Take a good photo. Shoot straight down in daylight, no shadow, fill the frame, then come here and use Light and dark to make it pure black and white.

Burning a screen instead of cutting? Islands are fine on a photo emulsion screen, the mesh holds them. Bridges only matter for cut stencils (paper, vinyl, spray paint).