[alt-photo] Re: sizing options for color gum

[Kurt Nagy]

I found good results with a solution of 3.5% Knox gelatin + gesso on COT320 paper but a pain in the butt to mix, coat and cleanup so I going to just work with the PVA for now.

I never got any good results with spray starch or just gesso.  Never tried any of the hardeners or toxic chemicals.  Seemed like too much of a hassle



On Jan 15, 2012, at 3:39 PM, "Gordon J. Holtslander" <gjh at shaw.ca> wrote:

> I'm starting to work with gum printing again.  I want to start doing color gum from digital negatives.  My previous gum work was all from very large format pinhole negatives.  I've been using Maidstone paper.  It worked well with my pinhole negatives.
> 
> There are a more sizing and hardening options than when I was doing gum.   I used grocery store knox,  hardened chrome alum.  I used to coat my paper with gum and then soak in chrome alum to harden.
> 
> Does higher bloom gelatine make a difference in sizing?
> 
> I can't use formalin because I am allergic to formaldehyde, and won't use glyoxal for the same reason.
> 
> The new options are Gamblin PVA and gluteraldehyde.  I'm prepared to make a "fume hood" in my darkroom to deal with gluteralehyde fumes - I believe its too cold in Saskatoon, SK to size and dry outside in the winter.  Is gluteraldehyde worth the effort or should I use Gamblin PVA or chrome alum?
> 
> What are peoples experience with sizing?   I've done some preliminary work with Gamblin PVA - it looks promising.   I tried undiluted GAmblin - but it was way to glossy. 2:1 Gamblin appearw workable.
> 
> Anyone using something different than PVA or hardened Gelatin?
> 
> Gord
> 
> 
> -- 
> Gordon J. Holtslander
> gjh at shaw.ca
> 
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo
>