Screen printing exposure unit screens can be both the most rewarding. And the craziest part of screen printing. Good movies are good screens, and good screens are good prints. Poor exposed screens are a nightmare.
Prepare foil and coated dry screen.
Tap the entire screen to make sure the entire emulsion is dry . check the edges of the screen where the emulsion is thickening or dripping. If something feels damp, give it more time in a dry box.
1) Turn on the power (big green switch)
2) Check that the light and vacuum switches (large black switches) are in the “auto” position.
3) Set the timer. The duration will depend on the emulsion and graphics used. Finding the right timing for each screen printing. Exposure unit and emulsion combination is a bit of trial and error. This link will take you to a guide with key screen printing exposure unit for some common emulsions.
The green numbers are use to set the time. Use the black up and down arrows on the clock to adjust the green numbers up and down to the time. The yellow arrow lets you navigate through the numbers. Mode button to sync the red. Numbers with the new green numbers. The time shown in the red (top) numbers is the time the screen will exposed.
Lift the table top,
this is a hinged frame around a black neoprene blanket.
4) Place your film positive side up on the glass. All images and font should be in the correct orientation (nothing upside down or upside down).
5) Place the screen on the foil with the mesh side down. Center the film inside the screen, images too close to the edge of the screen will not be expos.
. To get a good screen template, the contact between glass / foil / mesh needs to be tight and tight. Any gaps will allow light to bend around the edge of the film and bring out the fine lines and edges of the picture. Put the string on the screen and glass. It doesn’t matter if it goes beyond the field of view. Close the hinged cover on the light table and snap it into place on the front. The order (from top to bottom) will be as follows:
Screen (web side down)
7) Move the black vacuum switch from “auto” to “manual”. This will make the vacuum turn on and be very noisy. Leave the vacuum for about a minute. With the vacuum on, I like to grab a few books and fill the inside of the screen (on the blanket) with heavy books. Place the books in the space where your art is. This will aid the contact between the screen. The glass and prevent light from slipping off the edge of the film.
Above the switches there is a button called “Press the button to activate the timer”. Press this button immediately. This will set the light and vacuum for the time set above. Now you can step away from the table and let it do its thing.
Take out the books and unlock the table. Leave the foil on the screen printing exposure unit and take it away to clean the screen.
Any gaps will allow light to bend around the edge of the film and bring out the fine lines and edges of the picture. Put the string on the screen and glass. It doesn’t matter if it goes beyond the field of view.