U of S | Mailing List Archive | alt-photo-process-l | brush vs tray size for gum

brush vs tray size for gum

Hi All,
This weekend was time for sizing paper, and since I was doing small sizes (11x14's) I decided to tray size instead of brush size to see if it had any added benefits to brush sizing.

I was sizing with gelatin glutaraldehyde as usual. I did use a piece of it right away, same day, and had no problem with the sizing not being hardened and producing "magenta squares" as did Carmen. However, I was using glut that I bought from a medical supply house (now available at the Photographer's Formulary) and not Black Magic. The gelatin on my paper was not slimy in any way so I know it was hardened. I am still not sure why Carmen got that problem, and am wondering about the suitability of Black Magic, therefore, with its added sulfite. It sounds like the same result I had when I tried Terry King's advice to use unhardened gelatin and got black squares.

With tray sizing and cautions with glut, I gelatin sized the paper first, and then the next day I soaked the sized paper OUTSIDE in a tray of 50ml glut to a gallon of water. That worked well, but I would only tray size if the hardening part could be done outside to minimize fumes produced by the surface area of a whole tray of hardener, whatever type--glut, gly, formaldehyde. (When I brush size I keep the solution capped inside a thermos and pour out a cup at once.) The gelatin paper went in "slimy" feeling, and went out unslimy.

The paper works fine but I learned a couple things: paper tray sized with gelatin will sink to the bottom, not float as does brush sized paper (except Arches) so if I am going to leave the paper soaking for a while it needs to be face up. I learned that the hard way. Back to floaters and sinkers, Mark.

The paper does curl less than brush sized, but it doesn't seem worth the added trouble of trays. This is the only benefit I can see. Oh, maybe more evenness of sizing? I don't know this one yet...will have to print all papers.

My husband set up an ingenious "clothesline" for me--a rung ladder on its side has plenty of hanger-ready rungs.

I learned another thing the hard way: I printed 4 prints on the unsized but shrunk paper with a cyanotype layer, put the paper through the hot gelatin sizing process and didn't THINK that the 140-whatever degree gelatin would shrink the paper even more and make registration a B---H but you bet it did--warped and shrunk. Luckily only 4 prints ruined. DUH. Or, as Clay says, DOH.

The bottom line is that brush sizing is sooo much easier and works well and uses way less gelatin--I sized 24 11x14s with a a liter of 3%, and normally I can do that many 16x20s with the same. I don't think even with small sizes I would tray size...

That's all my truly exciting weekend experience!