Re: Clearing Gum Bichromates
Judy Seigel (jseigel@panix.com)
Sat, 13 Jan 1996 02:07:39 -0500 (EST)
On Sat, 13 Jan 1996, s carl king wrote:
> Another thing I have observed is that you must renew sodium bisulfite
> on a regular basis. If old or exhausted sodium bisulfite is used
> to clear papers it will stain the paper blue. This has happened to me
> with both Fabriano and Rives papers hardened with chrome alum, and
> I believe (though not positive) also with formalin.
As noted, gum printing is very different from carbon
printing, but I will mention that I have re-used sodium bisulfite until we
were both old & exhausted (at which point it did exactly nothing
clearing-wise) & have not seen blue stain -- the paper being either not
sized extra or hardened with formaline/glyoxal.
Judy