Double Coating of Platine

TERRY KING (KINGNAPOLEONPHOTO@compuserve.com)
Sat, 28 Feb 1998 04:00:40 -0500

Message text written by Stephen R Harrison
> What are the advantages of double coating. What are the effects on a step
wedge
>contact printed between one and two coats? it obviously expensive doing
two
>coats on large format. Feedback?

Stephen

Double coating can help to increase contrast but it probably a lot cheaper
to get the negative right first when one coating will quite sufficient to
achieve a full range of tone.

>Second question : In the sodium dichromate method of contrast control, is
>any restrainer such as Hydrogen peroxide needed for the KOx #0 solution,
>that is no drops of sodium dichromate.? Is the evident grain of the pure
>Kox solution paper dependent?

If one gets the negative right these contrast contrast become irrelevant.
At best they detract from the quality of the final print. I know that half
the world, or more, uses these controls but that does not mean that they
work as well as making a negative with the right density range and
gradation, But if people want to use twice as much platinum or introduce
unnecessary chemicals into their coatings when one negative and one coat
will do the job, then that is up to them.

Terry King

Stephen Harrison

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