U of S | Mailing List Archive | alt-photo-process-l | Re: gum preservatves

Re: gum preservatves

Hi Guido. Probably both 1g per 100g gum or 2.5g per 100g gum are correct
values since it works for us. I thought if 0.1% is good for food then it
can be also good for gum arabic solution. I just want to do it to see what
will happen...

Thanks for the tip! I also want to try casein ASAP and I can surely use a
faster coating solution (with paper negatives). You increased my
motivation for casein!

Will ask you about acrylics later... (Have to go out now.)


4 Eylül 2008, Perşembe, 5:06 pm tarihinde, Guido Ceuppens yazmış:
> Hi Loris,
> I am not sure what the "correct" amount of sod benzoate per weight of
> (dry)
> gum is. I just asked the importer advice on preserving the gum mixture. I
> also read somewhere about "sour" gum being faster (Kuhn?) but never tried
> it. If I need a faster reacting mix (as when using RC photo paper as
> negative) I use casein instead of gum: a speed gain of approx 2 stops for
> me. I also use PVA (Mowiol), a mixture of mowiol with paint and pot
> bichromate can, even after 2 weeks storage, be used for printing without
> loss of speed or quality. Mowiol however prints slower than gum - approx.
> 2
> stops slower in my set-up. I mainly use both casein and mowiol when
> printing
> with Acrylic paints.
> Greetings,
> Guido