Photo Emulsion test no. 7

May 14, 2015

Researchers:Kevin Pomerleau/ Daniel Chiaccio
Room Temperature: 65 degrees F
Humidity: Dry

Materials: Macdermid Plus 8000 Universal Resistant Emulsion, 17x 15″ screen, Speedball Screen printing ink with extender, Exposure unit, Opaque Black Trash Bag, 5 lb. steel plate

Abstract: to see if a high quality image could be obtained on a screen that exceeded the size of our exposure unit, and was able to be used on our new Filbar Press

Procedure: Using a 14″ scoop coater, we coated a 47×34″ white 195 mesh count screen. After letting the emulsion dry for 45 minutes under ventilation, we exposed a pre-made transparency using both halftone and text (the same transparency from test no. 6/refer to “How to halftone an image in photoshop”) by placing the transparency, emulsion side up, onto the exposure unit with the emulsion filled screen face down over it (emulsion to emulsion) while letting the screen overhang the unit on all sides. We then covered the entire unit with an opaque black trash bag and a large steel 5 lb. plate and set the exposure time for 7 1/2 minutes. Once the exposure was finished, we removed the weight and trash bag, and walked the screen to the washout booth (in a non light safe room) and washed the screen out. Due to the size of the screen, and the unexposed areas which overhung the exposure unit, we used a non photo sensitive screen filler to fill in unexposed areas of the screen. Once the screen filler dried, we printed the screen.

Conclusion: We found that with an increased amount of weight to the screen during the time of exposure the screen was able to expose properly, and gave us the same amount of detail as we did from test no. 6. The emulsion withstood a print session on the Filbar, and showed no signs of breaking down after a large quantity of prints. The only major difference was the handling of the screen after exposure and filling in areas of the screen with non photo sensitive screen filler that were not able to be exposed due to the overhanging from the exposure unit.

 

 

 

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