Copy of: Oil/Alum & RC Gum negs.

TERRY KING (101522.2625@CompuServe.COM)
21 May 96 12:45:24 EDT

---------- Forwarded Message ----------

From: TERRY KING, 101522,2625
TO: Robert, INTERNET:RNEWCOMB@UGA.CC.UGA.EDU
DATE: 21/05/96 17:00

RE: Copy of: Oil/Alum & RC Gum negs.

>
Robert, Hello

> Two questions for you if you have the time.
> 1) Can a bath of Formalin be used to "condition" gelatin that I coat for oil
> prints instead of chrom alum ? Dilutions? Time ?

Perhaps but in weak dilutions. I use chrome alum at a dilution 0.1 of 1
percentage point, making up a small amount of solution and adding it to the
liqid gelatine to acieve that dilution. I do not use formalin for all the
reasons recently mooted.

> 2) RE: tonal separation negs on RC paper for gum prints.
> A highlight neg made from a large pos. will record the highlight information
> and nothing else. The shadow areas in this highlight neg will be without
> density. Won't these areas later print as black in the gum ? It seems like
> one would need some sort of mask as well as the sep. negs.
> Thanks ! I hope you are doing well. Robert Newcomb
>
As the highlight neg will be used for highlight tones nowhere in the print will
be darker than that tone so that the other negs will be able to print over it.
In the shadow detail neg the highlight tones will be so dense that they will not
print and the same will be true in proportion in the middle tones neg. It
explains itself when you do it.

Let me know how you get on

Terry