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| Posted on 6/21/07 at 05:16 AM | |
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First, prove to yourself that the stencil works. Don't waste a whole screen for a test, coat a very small area and after it dries, cover it with a 10 step transmission gray scale and a dime. Expose. The gray scale will tell you if your stencil is getting enough exposure to your lamp if Step 7 does not wash out and stays on the mesh. The dime is sure to stop all light unlike the toner from your laser printer. It will demonstrate how the stencil will dissolve and go down the drain ifit wasn't even touched by exposure. Office laser printers are notorious for not being able to stop UV light. Mike Casey makes very fine paper, and I don't think that contributes to your problem. You mention that you double the positive, so that reinforces my guess that your toner is not doing the job. You do not mention your light source, but you will have better success with a faster exposing emulsion like Ulano QTX because it requires less energy to crosslink - which will shorten the amount of energy that is seeping through your positive. You write that you have just switched to RLX. RLX is a fine emulsion, but we have a pre-sensitized dual-cure QX-1 that costs less money and has a shelf life of more than a year. Many people say that RLX looks solid with its lovely magenta color, but I always used TLX because I could register multicolor prints faster since I could see through the pale green/blue color - and it exposed 20% faster than RLX. I have not stirred diazo into emulsion since I switched to pre-sensitized blue/green QX-1. Of course, if you switch to QX-1 which is SBQ sensitized, you will lose the visual indicator that diazo emulsions have of changing color when exposed, and you will be forced to use a gray scale to monitor your exposure. You are surrounded by Ulano distributors in Charlotte, Greensboro and Raleigh that should sell gray scales. T1015 http://www.stouffer.net/TransPage.htm#transmission%20step [Edited on 10/3/07 by richardgreaves] ____________________ Richard Greaves, ASPT Ulano Corp. New York Technical Services 718-943-1338 direct | |
  
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