>Absolutely,
>
>I am finding out that their are many more variables in experimenting with
>carbon then their are in Gum. Looking at your cross sections, If I assume
>that the pigment has a considerable effect in masking the penetration of
>the light, then I would expect high contrast and low relief when alot of
>pigment is used. Conversly I would expect a high profile and lower contrast
>with less pigment. Therefore th minimum thickness depends on the depth of
>penetration of the light. Although if everything was linear I would expect
>that since the gelatin is thicker with the light pigment it might look very
>similar. Is this analysis correct ??
Your analysis is right on. The two cross sections I described, assuming the
proper balance of pigment and gelatine thickness, would give similar images
in terms of contrast, when viewed on center. However, the dimensional
effect would be much greater with the thick gelatine tissue "when viewed
somewhat off center."
>
>My original question was concerned more with the contradictions in a number
>of articles/books I have read, then the *ideal* thickness. In answer to your
>question the thickness of coating can be measured with a micrometer which is
>accurate to .0005 (half a thousandth) or a top quality digital vernier caliper
>which has similar accuracy.
Please tell me more about these instruments and the procedures for
measuring gelatine thickness.
Regards,
Sandy
>