Re: photgravure sensitizing solutions

Sil Horwitz (silh@iag.net)
Wed, 11 Dec 1996 13:15:14 -0500

>Gary Kolb's book Photogravure - a process handbook which calls for a 3.5%
>potassium dichromate solution mixed to the following proportions:
>35 grams of potassium dichromate dissolved in 1 liter of distilled water.

>Deli Saccilotto's book, Photographic Printmaking Techniques, a 3% potassium
>bichromate solution mixed as follows:
>3 grams of potassium bichromate dissolved in 1 liter of water.

Must be an error - a 3% solution would be 30 grams in 1000 ml (1 liter).
Don't think book proofreaders are error-free!

Also, bichromate and dichromate refer to the same material. It depends on
the era at which the chemical was named - "bI" is Latin for "two" and "di"
is Greek for the same number. Chemicals are usually named by the originator,
then a committee gets it and tries to make the name consistent with certain
guidelines.

Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net