Screen Printing Forum

I am using a homemade light box with 3 unfiltered black lights. My artwork is printed on vellum paper. I was experimenting with different times and can't seem to get it right. First, just a big square the size of the paper washed out. Second, the design washed out but then the emulsion around started to wash out as well. And the last time nothing washed out at all. Is vellum not transparent enough or am I just missing something else? thanks for the help

nah its not the vellum...

prolly the lights and time.

You should prolly keep a record of exposure times and results.

Distance from light to screen also.

also...your print might not be opaque enough...prints on velum are know for not being dark enough, some products are sold that you can spray on your velum to make the print darker.

I'm pretty sure the problem was caused by using old emulsion and/or high heat and humidity. I just purchased a fresh gallon and it seems to be working much better.