[alt-photo] Re: Sizing Problem and ?

[Christina Anderson]

Johnny,
I once sized a batch of paper outside in the garage with gelatin that was too cold by the time I got to the last sheets, and boy was that a PITA. I ended up cutting off sections and discarding the parts that were unevenly sized.

However, my experience with glyoxal is similar to your description. I found it felt...for want of a better word...crystally/grabby on the surface, and it speckled. I abandoned it for glutaraldehyde which sizes very smoothly. I also like formaldehyde very much but in my environment, cold in the winter, I have to hang it to dry in my house and it outgasses so badly that my eyes sting in the room the sheets are hanging. I could size with it in the summer just fine. No need to do so now because glut works for me better.

BTW I know Don Bryant sizes just fine with glyoxal as I have used some of his sized sheets so I don't blame glyoxal per se, just the way I work with it.

You have described speckles of color which leads me to believe that staining is happening on the paper where sizing is not, probably on the topmost fibers sticking up that did not get sized enough. If the speckles are in the depressions of the paper that may be another cause.

I might suggest you size again with another layer of glyoxal gelatin to even out the coating. OR you could buy some Gamblin PVA and give the paper a light coat of that on top of the already sized paper, mixed 1+2 water, to try to get by the issue. Try it on one sheet.  

Alternately, see if your exposure may be too long.

Diagnosing gum problems via email is always like shooting buckshot into the air. Maybe one suggestion will stick. I get students with these unusual problems and I have to literally watch them gum print to determine the cause. For instance, one student had severely stained highlights. Lo and behold, one of her three negs was a positive. Another coated the paper too roughly. Another used too much dichromate. One, who had layers that never stuck, she thought the stock pigment mix had dichromate mixed in already and never bothered to add dichromate. I've seen it all...in fact, I have compiled a list of these possible mistakes that I will include in the gum book because some are just too funny. And then some produced wonderful gum prints because of the mistakes.

But sizing is the biggest PITA if there is an error in process because it crops up later in masked ways.

Maybe this helps, maybe it is another issue entirely.
Chris

Christina Z. Anderson
christinaZanderson.com

On Dec 5, 2011, at 6:45 PM, Johnny Brian wrote:

> In the last few months, I've been learning to make gum prints. In the beginning I printed on unsized paper to simplify the process. I made some progress so I decided that I should size the paper before I started printing multiple layers. I tried a number of papers but settled on Arches Platine. I sized a couple of small pieces with 3% gelatin/glyoxal and printed on them - I didn't see much difference with a one layer print - but at least no detrimental effects.  So I sized about 20 pieces of 11x15 pieces of paper. However, once I printed, the paper now prints with very flat muddy midtones and there are speckles (freckles) of color in the midtones. I've printed several different pieces, it all seems to be the same. I've also printed on some unsized paper and it prints what I consider "normal" - not that I'm any expert. It seems that something must have gone wrong with the sizing. I'm looking for advice about what to do to salvage the paper - if possible. Any collective advice 
> would be appreciated before I begin experimenting on my own. Is it possible to remove the sizing by soaking in hot water, or should I try applying a new coat of sizing on top of the old sizing? Below is how I sized the paper - 
> 
> Sizing - I made 250 ml of 3% - 7.5gm 250 bloom gelatin from B&S in 250 ml distilled water. I allowed the gelatin to soak about an hour and then heated it slowly on the stove until it dissolved. I didn't check the temperature - I stopped heating when it appeared that all of the granules were dissolved. I put the solution in a big insulated sippy cup and added 5ml glyoxal and stirred to mix. Applied gelatin with a sponge brush and allowed to dry for several days. 
> 
> Thanks for any help,
> Johnny Brian
> _______________________________________________
> Alt-photo-process-list | http://altphotolist.org/listinfo