DIY Screenprinting Tutorial

EMULSION

Emulsion is the liquid that will dry on the screen to create a stencil. Speedball Diazo, the most commonly found in art supply stores, costs $20-$30 per bottle, and if you don’t buy a kit that already includes it, you will also need to buy sensitizer ($6-8). Mix the two together (as per directions on the sensitizer bottle) and allow it to settle for an hour or two. Once you have it activated, immediately refrigerate after using, with the expiry date clearly marked (3-6 months). Why? You will always get an overexposed screen once your emulsion’s gotten too old.

The next step is best done by candlelight, red light, or in a dimly lit room. Using a spoon, lay down a bead (narrow strip) of emulsion and spread evenly across the screen holding your squeegee or old cassette case at a 45 degree angle to the screen. Be careful to not leave any big blobs or streaks as they will either expose unevenly or just simply won’t wash out. You are aiming for a thin layer on both the top and bottom of the mesh. Set to dry in a dark area (ie: a closet, using a towel to fill in gaps which allow unwanted light in, or cardboard box covered in blankets or lots of heavy black plastic).

Once you have finished this step, set face down on blocks. This allows the emulsion to gravitate towards the side you will be exposing, which makes for a better exposed stencil. A screen should take about a half hour to dry in a well-ventilated closet. Or, let it sit overnight and it will be dry by morning. I like to use a fan to help it dry quickly. Do not leave your unexposed screen to sit for longer than 24 hours or it will expose itself!


TRANSPARENCIES

Photocopy your design onto two transparencies at a copy shop or a home printer. The transparency must be black- no grey tones. The objective is for your image to be as opaque as possible: hold your screen up to the light and try to look through it! If you can read something through it, it’s not dark enough. Special transparencies ($3) are available at printing supply shops which allow maximum toner to rest in the textured surface.

EXPOSURE

Use reading lamps with 150 w bulbs (will take 45 minutes for a 8×10 screen), or find a 300 W bulb and lamp for shorter exposure times (10 minutes). You’ll need to adjust the height of the lamp based on the size of your screen as per the Speedball chart at the end of this section. Cover table in black cloth to prevent light from bouncing back up to the underside of your screen, and additionally, make sure no light is able to leak under the edges of your frame.

IMPORTANT: Set your transparency on the top of the screen UPSIDE DOWN (ie. words reading backwards). Cover transparency with glass to prevent light from leaking under the edges of the image. Use a timer, and after exposure, cover screen with a towel to protect it from light as you move it to your rinse station (bathtub or shower enclosure).

Some people like to use the sun to expose their screens! You may not get consistent results depending on cloud cover, time of day, etc. To expose with the sun takes only a minute or so, but if you do want to try it make sure that no light touches the underside of the screen, so use a towel or a box to shelter one side.