Screen Printing Workshop first test

Intro

On February 18, 2009 I made my first attempt at creating a screen using Diazo photo emulsion from Speedball. Details to follow. --Nathan

Preparation

Materials:

• Lightbox (with 6 20 watt daylight fluorescent bulbs, distance from screen: ~7"
• 12"x10" Dick Blick screen #94708 (upc:651032 947087)
• Speedball Diazo photo emulsion kit
• Speedball 10" squeegee
• NOTE: It would have been good to invest in a scoop coater as well
• Flat, heavy materials. I went with Flash MX Bible, Visual Basic 6 Black Book, SAMS Visual C++ 6, SAMS Teach Yourself LAMP & Basic Electronics text book.
• Clothes you're not worried about ruining
• Patience

Application

• Diazo photo emulsion kit requires mixing sensitizer (Black) into the base emulsion (Blue) to activate. Do so and mix vigorously (Resulting mixture turns green.)
  • Directions state emulsion can last for up to 4 months when stored in refrigerator.
• Carefully applied emulsion to both sides of screen with Speedball squeegee. This is where I could have made less mess with a scoop coater.
• After checking that both sides were coated as evenly as possible I IMMEDIATELY took the screen to dry in a dark arrid place. In my case I used my oven (no heat necessary). According to instructions, dry the screen with the flat side down, but elevated.
  • screen appeared to be perfectly dry in 1 hour, could have gone with 45 minutes probably.
• Do not expose screen to light until you are ready for printing. This is why I need to build a drying box.

Exposure

• I burned the screen for 15 minutes, checked it, uneducated guess is that it needs more time to expose. Check again in 15 more minutes. (10:34 PM)
  • Now is a good time to note that I should have attached my positive to the screen so when I checked it the alignment wouldn't get messed up.
• I decided to let it stay for another 30 that way if it overexposed I would have a high point of reference. From what little experience I have it doesn't seem to have changed much. The emulsion basically just gets slightly more transparent.
• After 45 minutes I pulled the screen off the light and washed out the print areas with my high pressure spray nozzle. It takes a minute or two for the areas to start clearing out (I was worried) but then slowly they will empty out.
• Letting screen dry completely will I prepare my kitchen table for test prints.

Result

My first custom shirt
Full set on Flickr

Came out way better than I could have imagined. Only a few things to note:

• The color blends into shirt fabric too much. This isn't so bad on light colored shirts, but on dark/black it's nearly impossible to see. I'll have to research further on types of ink to use (went with water solvable for this attempt) and step up to multi-color prints at some point.
• A finer screen mesh, which could be a little more expensive, would yield better results on firmer surfaces like paper.
• DEFINITELY need to learn how to stretch my own screens for saving cost.
• For future screen burns, I'm thinking of incorporating some kind of test pattern in the corner or my screens that I will mask off at printing time. This will make it easier to check the progress of exposure without compromising the artwork.