Silkscreening on Float Glass With Mica
I’ve always wanted to try silk screening on glass, and this past week, I got the chance. I was surprised at how easy (relatively) the process was. Making the silkscreen doesn’t lend itself well to video (lots of waiting around), so I’ll outline that process here:
Start by creating your design. I used photoshop to create this pattern of 5 brine shrimp that I would be creating a screen of. [TRIVIA: Brine Shrimp are also known as Sea Monkeys, and are the only critters that live in the Great Salt Lake.]
I printed this design onto a transparency. The black lines/patterns will block the light from the screen.
Step 2: Create the screen. I used this kit from CraftyPrinters.com, which was easy to use and relatively inexpensive. The part I like is the screens are prepared and ready to use, so I could make a silkscreen and be printing with it the same day.
The kit contains 4 prepared screens, 1 sample size for tests, 1 magnetic assembly that holds the transparency and the screen together during exposure. (It also includes a little squeegee and some screenprinting ink, in case you want to make a shirt later)
Start by turning down the lights, you don’t want to expose the screen too soon. Place the screen on the black assembly backing, add the transparency with your design, and then add the plastic top. It sounds complicated, but it really isn’t.
Now, you need to expose the whole assembly to a light source. The manufacturers website has a great tutorial about how to build your own light assembly. I used one of my photography lights on a boom tripod, and it worked great. If you don’t have photography lights, the instruction book also tells you how to use sunlight to expose the screen.
After exposing the screen for the appropriate amount of time, you turn the lights off, remove the screen and place it in tap water in a completely dark place for 10+ minutes. I put it in a tupperware inside my toolbox. Not very exciting to look at, but it did the trick.
Step 3: Wash out the screen. The instructions said to use a synthetic brush to wash out the loose emulsion, but I found it to be very easy to put the screen on a piece of plastic mesh and spray it with a squirt bottle. Worked like a charm. Then put it somewhere safe to dry. Outside in the sun is a good choice.
The Printing Medium
The printing medium is made with Thompson Enamel Water Based Medium and copper mica.
I mixed in a 2:1 ratio, medium to copper. So, 1/2 tsp medium, and 1/4 tsp mica. Mix until creamy and smooth. You can thin it with water later if it’s too thick.
My project called for 9″ x 9″ square pieces of float. To set up the work area, I poured out the medium on a small piece of glass for ease of use. The float glass squares are clean and ready to use. I opted for a folded postcard rather than a squeegee as I wanted a more flexible edge. Once all that stuff was ready, I printed like mad.
One of the nice things about this screen printing kit is the mesh is a bit stiff so it doesn’t need a frame. That makes it easy to use and less clunky.
After screen printing 60 sheets of float glass (with 4 prints each, for a grand total of 240 prints), I added them to another sheet of float glass that was already coated with enamel and fused. I did not have to cap the mica because the medium made it stick to the glass and fuse very solidly, the prints are very metallic and bright.