Re: Diazo Photo Emulsion Chemistry & Gum Printing
Are you trying to come up with an emulsion to coat silkscreen? If so, the simplest is to just use gelatin. Knox from your supermarket works fine. It is colorless, so you might want to wipe on some food dye after it's developed to make it easier to see and register. Gelatin emulsion can be easily removed with household bleach.
For silkscreen you need an emulsion that's either blocking or not blocking, so gelatin is ideal. I have never tried using gum but I suspect it would not work well.
I have always wondered about the sensitizer in Diazo emulsions but are you sure it's potassium dichromate?
By the way, plain gelatin as silkscreen emulsion worked great with oil based inks. I've had no experience with water based inks so do not know how well it would work.
Hope this helps.
On Jan 31, 2009, at 2:10 AM, redrocket wrote: