So - someone I work with at my day job has been asking me about "screenprinting" and my process, in general. Well, recently I was lucky enough to be asked to create a print for a friend who just graduated barber school, and thought that it would be the perfect opportunity to create this post, and maybe explain some of what I do. Please ask if there are any questions...
Step 2 - Prepare the artwork
So now that I have a design, I need to separate the colors and burn some screens. For my screens I use photo emulsion (science behind it, and what it looks like). I'm a perfectionist, and this gives me the cleanest lines. I also hate waiting, so I use a quicker setting and burning emulsion than I probably should. The screens are prepped by applying a thin coat of the emulsion on each side of the mesh. Screenprinting is basically forcing paint through a stencil (the emulsion), and the mesh acts as a bridge between the open areas of the stencil. It makes it possible to print, for example, the letter "o" without those pesky bridges holding the center of the "o" in place (like in spray paint stencil letters the Army uses). The emulsion on the screen has to dry for a bit, so while that's happening, I prep the color separations.
In screenprinting, you can only print one color at a time ("split fountain" is a technique to print a gradation of colors, but it is faaaaar from consistant), so each color in your design is a separate screen. Using Illustrator like I do, it's easy to simply select everything of each color, hide everything else, and print a film for each color. I use a wide format Epson inkjet printer, and use waterproof transparency film. I print each color black as a "positive", and use this to burn the image into the screen emulsion.
In the picture above, you can see the burn setup. I use UV bulbs in conventional lamps (emulsion reacts to the UV spectrum, that's why you can burn screens in sunlight) hanging over my work table. The set-up from bottom to top is - foam to fill the space the screen frame creates, black posterboard so there is no light bounce, screen - ink side down, transparency, and glass to hold the transparency as flat and as close to the emulsion as possible. Each transparency is printed black to properly block the UV light from the emulsion. During this process, the UV light is hardening every area of the emulsion that isn't covered by the black of the transparency. So, ink is only going to go through the area marked by the transparency
After the screen has been under the UV light for the right amount of time, the areas not hardened are washed out in the sink by a high pressure blast of water
In the picture, the light green areas will be mesh only - all of the emulsion will wash away.
In the design I came up with, there is a large area of yellow surrounding the entire design. Instead of printing a transparency, and using up a ton of black ink, I decided to use an old technique of cutting the design by hand in rubylith.
In these 2 photos, the red is rubylith - it acts as a UV barrier like the black image on a transparency. So where it is red, I will eventually print that area yellow.
So, at this point in the process, I have a screen for yellow, grey, red, blue, and black.
Here is a closer look at one of the finished screens - green is emulsion, yellow is mesh.