RE: Carbon on glass
I have tested adding sugar to gum and didn't notice any difference either. I suspect that in the old formula they were mixing gum from powder themselves, so the gum might act as plasticizer. The premixed gum probably has some in it already or a more modern version of plasticizer has been added, but that is just my guess. Dave > -----Original Message----- > From: Judy Seigel [mailto:jseigel@panix.com] > Sent: Tuesday, September 11, 2007 5:43 PM > To: alt-photo-process-l@usask.ca > Subject: RE: Carbon on glass > > On Tue, 11 Sep 2007, Marek Matusz wrote: > > > Hey Cor, You are correct that back exposure is no go with BL tubes, > > the image would be very diffused. I did use sugar in my > carbon recipe > > since most of the sources reccomend it, I am not sure if it > is needed > > for glass work. > > Speaking of sugar, I'm curious if anyone here has ever tested > with and without sugar. I had several old formulas for gum > printing that called for sugar, which my tests showed made no > difference at all -- although perhaps with carbon it does, > and it just got added to gum formulas out of habit, like the > buggy whip on early autos? > > ??? > > J. > >
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