I got a quick question regarding screen exposure time.
I made a cheap exposure unit using a 500w halogen light. When the screen is placed on the exposure unit, it is 21 inches away from the light. About how long should i expose a 125 & 160 mesh count screen? oh also the designs arent too detailed.
I did it for 16 mins a couple of times and where the page that had the art work was at begins to wash away. i am using vellum paper. Im exposing for too long right?
I use a 500W halogen too, without the glass.
At 16" over the screen it takes 12.5 min. to burn a screen. So far it has worked fine.
I use transparencies. I used to use 2 transparencies, one on top of the other to achieve a darker black, to block UV, now I am going to try toner aid, from silkscreensupplies and see how good it is.
If you ever plan to use a halftone, you will need to move away from your dependency of 2 layers.
I've used a couple laser printers to produce my film and neither one has ever needed any toner aid not being stack 2 high. In fact my laser transparencies were so good that when as i move to in inkjet, i 'm needing to turn down my exposure time.
Be sure that you tell your printer, not to save toner. Many laser printers turn down the toner to save costs, but for film, this is a bad idea.
For film i like the kimojet laser film.
What sort of exposure unit are you using. It might be the film is not being held tight on the mesh?
fred
Thank you fred..I am just thinking in the near future start with half tone, I set my black toner to +10, the maximum, but still it looks not too dark, so I didn't even try it. What kind of printer you have?
In fact I just hate the two layers thing, it is an additional step.
I started using a 500w quartz halogen and vellum off my laser printer. Using dual cure emulsions, it took around 18 minutes to expose the screen. Photopolymer emulsions will expose quicker, but to get your times down you're going to at least have to go to unfiltered blacklights, or metal halide.
16min exposure time too much? 
