Thats how it used to be done. Each color was printed on its own
semirigid (usually Vinyl) sheet and then combined manually onto a sheet
of Temporary (Non-hardened) Support paper which was then transfered to a
final support. Because the temporary support paper changed size each
time it was wet and then dried (3 times for a tricolor print)
registering the three layers was a difficult and time consuming
process. Add to that the fact that the pigment papers (and the Bromide
B/W Prints if Carbro) also stretched /shrunk. etc and you have an idea
of one reason the process had a reputation for being so difficult.
Modern multicolor printers use pigment films coated on dimensionally
stable plastic (or RC papers) and print out all colors onto a single
sheet of plastic which is then transferred to paper. All this is
accomplished through using a register punch and pins(similar to the
Dye-Transfer procedure).
For more information on this modern Pigment Transfer Technique see the
UltraStable Web Site: http:// www.ultrastable.com
Regards to all,
Charles Berger
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