Screenprinting Setup
Supplies
Exposing & reclaiming screens
- Speedball photo emulsion (& catalyst) Suppliers: Dick Blick (online); Artist & Craftsman (usually stocked in store)
- screen reclaimer
- 250W photoflood light bulb Suppliers: Amazon
(tentative. looks like I didn't document the one that I was originally using & can't find it now.) - lamp that can handle the 400W bulb
- red bulb (optional) for that lightroom feel while exposing screens
- high pressure nozzle to clear ink and emulsion out of the screen
Ink
- Speedball acrylic permanent ink Suppliers: Dick Blick (online for quart jars); Artist & Craftsman
- Extender Base, for adding transparency to inks. Suppliers: Blick (online); Artist & Craftsman
Screens
- Mesh: 180T monofilament Supplier: Screen Printers Resource
Very important to use only monofilament mesh for sharp images on paper. - Nylon tape to hold down mesh
- staples (& staple gun) for stretching mesh
- tape to water-proof frames
- Haven't needed to purchase frames anytime recently.
Misc
- Painter's tape for holding down clips
- Registration clips
- Clothes line and binder clips for hanging prints to dry
Coating screens
Materials
- Emulsion
- Emulsion scoop
- Sturdy ledge (chair or something comparable with a sturdy vertical surface to lean the screen on)
- Red light bulb
Process
- Replace at least one regular bulb with a red bulb.
- Turn off lights; turn on red bulb.
- Mix emulsion. The Speedball catalyst instructions tell you to fill the container 3/4 full with cold water, which is always a tricky thing to gauge because the container is opaque & you can't really see what the water level is, especially in the dark.
- Lean the screen at about a 70° to 85° angle against something sturdy. The flat face of the screen should be facing outwards. It's important that both the top and bottom edges of the screen don't shift once the scoop is pressed against it.
- Pour the emulsion in the scoop, starting at one end and leaving a small amount all down the length of the scoop, in the bottom of the trough.
- Holding the back of the scoop, touch the edge of the scoop to the bottom of the screen.
- Tip the scoop up and wait until all of the emulsion has slid down to touch the surface of the screen.
- As soon as the emulsion has made contact with the screen down the whole length of the scoop, start to gently but firmly pull the scoop up along the surface of the screen.
- As the scoop approaches the top of the screen, start to tilt it back such that the emulsion will slide back away from the surface of the screen.
- As the scoop makes contact with the tape at the top of the screen, pull the scoop away from the surface of the screen. Try to do it in such a way that no excess emulsion is left on the screen or the tape.
Exposing screens
Materials
- red bulb
- lamp with ceramic socket
- 250W photoflood bulb
- flat surface
- armature to hang lamp
- transparency
- spray mount
- black paper
- painter's tape
- clean glass
- stop watch
- large sink
- hose
- spray nozzle
Process
- Attach lamp to armature and arrange it such that it is the correct height above the horizontal surface.
- Tape down black paper to flat surface.
- Turn off lights in the room with the exposing table. Turn on red lamp.
- Place the screen on the black paper, flat side down.
- Place transparency face down on scrap paper so that the image is backwards.
- Spray the transparency lightly. Spray it away from everything; spray mount is impossible to clean up.
- Wait 30-45 seconds.
- Gently press the image down on the "back" of the screen (the side that gets the ink applied to it). Looking at the back of the screen, the image should read correctly (not be reversed).
- Place the glass on top of the transparency. Try to arrange it so the edge of the glass lands beyond the area of the screen that has emulsion on it. Otherwise the emulsion under the edge of the glass gets exposed at a different rate from everything else and doesn't clean out neatly.
- Turn on the lamp and start the timer.
- Turn off exposing lamp. It's ok to turn on overhead lights.
- Clean out the screen right away.
- Gently coat both sides of the screen with water.
- Go back and apply the highest pressure jet of water possible to the entire surface of emulsion on both sides of the screen. Clean off any bubbles. Continue applying jet of water until the emulsion is washed out of the image on the screen.
- Gently dry off the screen with a kitchen cloth or paper towel.
- Let the screen dry thoroughly before doing anything with it. It's fine to have it exposed to light at this point.
Exposure times
Speedball emulsion & 250W BBA No.1 Photoflood
| Screen Size | Lamp Height | Exposure Time |
|---|---|---|
| 8 x 10" | 12" | 10 minutes |
| 10 x 14" | 12" | 10 min. |
| 12 x 18" | 15" | 16 min. |
| 16 x 20" | 17" | 20 min. |
| 18 x 20" | 17" | 20 min. |
In practice, a coated screen surface an inch or two larger than 18 x 20" probably needs more than 20 min.
Emulsion that was totally uncovered was thoroughly exposed, but emulsion that was under clear areas of the transparency had many pinhole spots in it. Lettering definition seemed good at 20 minutes.