Re: Sizing paper with gum and dichromate

Hi Loris,
I use a 3% gelatin solution, which is probably 2.8% because I use 4 packets
of 7g each Knox gelatin in a liter of water. Then when that is prepared
(boiled or just heated, depending on whether you forget it on the stove or
not) add 20ml formaldehyde to the mix and brush on. Use right away and toss
what you don't. Rinse brush immediately after use, too.

I have not used formaldehyde for 7 years...
Chris
----- Original Message -----
From: "Loris Medici" <loris.medici@altinyildiz.com.tr>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, December 26, 2005 4:41 AM
Subject: RE: Sizing paper with gum and dichromate

>
> Hi Christina,
> What is the percentage of your gelatine size solution and how much
> formaldehyde do you add to it?
>
> I know you're currently using glutaraldehyde as hardener but, what was
> your procedure when you were sizing with combined gelatine /
> formaldehyde?
>
> I plan to use 6% gelatine solution and a separate hardening bath. If it
> can be made without having a messy & hard to coat gelatine solution, I
> would like to learn the way of sizing the paper with gelatine +
> formaldehyde in one step.
>
> TIA,
> Loris.
>
> -----Original Message-----
> From: Christina Z. Anderson [mailto:zphoto@montana.net]=20
> Sent: 20 Aral=FDk 2005 Sal=FD 18:06
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: Sizing paper with gum and dichromate
>
>
> Good morning,
>
> I'm late on replying to this post but so it goes at Christmas...
>
> My problem with sizing with gum is this: in order to get the layer hard
>
> enough to be a suitable size, there will be some discoloration with
> the=20 dichromate that stays in and discolors the whites, in my
> practice. So by=20 experience I agree with kees. If I didn't harden to
> the point of=20 discoloration the layer was too soft. I tried clearing
> with pot metabi but=20 that whole procedure seemed like so much more
> work than just biting the=20 bullet and brushing on a hardened gelatin
> size (e.g. two separate wet and=20 dry cycles). Even so, the layer did
> not prevent staining.
>
> But I would assume somewhere someone out there has luck with this method
> who=20 is perhaps using lighter pigment loads, although my assumption is
> also that=20 since this method, quoted in the books long ago, never
> caught on as primary=20 practice means it just isn't as good as a plain
> old hardened gelatin size.=20 You know what they say about "assume",
> though... Chris
>
Received on Mon Dec 26 08:51:57 2005