500 watt work light and oiled paper positive exposure questions
I'm using a homemade exposure unit with a 500watt work light. Can anyone give me a ball park figure on how far the light source should be away from the glass/positive?
I am waiting for some transparencies to arrive, and have been experimenting with oiled paper and vellum positives. How long should it take to expose a screen with ellum? Oiled paper? With vellum, I found that the image washed out nicely, but the 11 X 17 area around it started washing out too...I think this is probably cause the vellum I used was too opaque...worked better with longer exposure time, but I startedto lose small details in a half tone. The oiled paper worked quite well on the first go...just wondering what ditsance light to positive and exposure times you guys are having succedss with...
if stencil comes off during washout, or is thin it is underexposed, but you are also correct if the vellum blocks too much light, it will always screw up/close in the detail - that's the sign of overexposure, coupled with a solid stencil.
somewhere in the middle. clear film works best, but you would be surprised what will burn a screen.