Re: Carbon Printing
s carl king (sanking@hubcap.clemson.edu)
Tue, 14 Nov 1995 14:39:55 -0500 (EST)
>The company was Franz Hanfstaengl of Munich/Germany but they stopped
>manufacture years ago.
>Be careful, this tissues could cause fog problems when not be stored under
>certain condition.
Regardless on how they are stored or how they are made, many pigment papers
(aka tissues) will have fog problems
The bottom line is this. If you want to work carbon/carbro you are going to
have to manufacture your own tissue. This seemed obvious to me fifteen
years ago when I began carbon printing. I agree with an earlier posting of Luis to the effect that the market is not there for commercial
manufacture of the tissue. I have know several people who in recent years
thought this to be feasible but after completing a market analysis decided
they were better off throwing their money in another direction.
As for the problem of fog, perhaps we can add some specificity to the
discussion. First, let us be clear that some pigments, for whatever reason, produce much greater fog levels than others. Try to identify and eliminate these pigments.
In my own tissue there is a very low level of fog that I can not altogether eliminate, on the order of log .05 or so. That is, if the Dmin of the paper base on which a step tablet image is placed is log .06, about the lowest Dmin I can get from a carbon image in the highest high-lights is of the order of log .11. I do not find this to be particularly troublesome, because Dmin, though specific in a technical sense, is very relative from an aesthetic perspective. Ater about 6 months, stored at room temperature, an identical tissue (same gelatin, pigments, dispersions, etc.) will have a Dmin level of between log .20-30, still usable perhaps with some negatives, but certainly marginal.
Freezing the tissue definitely retards the hardening of the gelatin (cause of this kind of fog), but does eliminate it. Out of curiosity, and in response to this discussion, I pulled out of the freezer some three-color tissue manufactured in 1989. It was altogether useless (gelatin had completely hardened), in spite of the fact that it had been in a below freezing environment for the entire period with the exception of a short period of time about twice a year when the freezer was defrosted.
Sandy King