Re: Carbon Printing
s carl king (sanking@hubcap.clemson.edu)
Thu, 9 Nov 1995 20:16:34 -0500 (EST)
Very happy to see the dialogue on carbon printing. Let me jump
in here with some comments.
First, to Stefan, I donUt understand why you sensitize the tissue
during the coating operation. It is not surprising to me that it
works, but you have less contrast control with pre-sensitized
tissue, and there seem few, if any , advantages. Pre-sensitizing
also introduces storage problems. Non-sensitized tissue can be
stored at room temperature for weeks and months on end with
no appreciable deterioration, not the case with pre-sensitized
tissue.
To Luis, I donUt understand your remarks about drying time. In
normal working conditions there is no way I can get coated tissue
to dry in 2-3 hours. Perhaps you did not pick up on the fact that
Stefan was pre-sensitizing his tissue? Certainly, if you were
referring to the drying time after sensitizing I agree with your
remark that the tissue should be used as soon as dry. I have conducted
carefully controlled sensitometric tests with carbon tissue sensitized
and exposed after completely dry at intervals of 1, 2, 4, 8, 16, 24, and
48 hours and can assure all that sensitized tissue gains in sensitivity
over time. The best procedure in my opinion is to expose the sensitized
tissue at a precise time period, otherwise there is sure to be some
difference in density.
Sandy King