"Unisize"

[buze]

I found very little documents on the sizing process; there are plenty of howtos on most processes, but they usualy contains phrases like "size the paper then.. blah blah" without details on how to do it.
Anyway, I picked some Gelatin (food grade, "Contains Sulphur Dioxide") and I was wondering if I could make a "unisize" which would allow to me use the same paper for all the processes I do at the moment. Cyanotypes, Vandykes and Salt Prints.

I was thinking of making a gelatin mix containing both sodium chloride and citric acid, and I was wondering if using that size would be detrimental to Cyanos and/or Vandykes/Kallitypes..

+ Any suggestions on dosage ?
+ Other ingredients needed ? (hardeners?)
+ Do I dip the paper, or do I "float", or do I coat with a brush ?

 

[Jerevan]

I think James M. Reillys' book is a good start on some ideas for different sizings. If I would be doing several types of processes, I would prefer doing just a basic sizing, such as gelatin and distilled water but nothing else in it, as different processes may react to any "extras".

I only have experience with brush-coating, which can leave brush marks, but I am sticking to it and I am getting better at it. I am doing bigger sheets and cutting them down into smaller pieces. Maybe floating is more efficient in a situation where you do a lot of sizing, provided you have the means to it.

The downside to unisizing is that you may have to do extra steps where you normally could combine sizing and sensitizing in one step. But if you can get your technique down, you'll be able to do a few batches of sized paper during an evening and thus it may be worthwhile.

 

[Lukas Werth]

Though I never tried such a thing, I am quite certain such a one-for -all would indeed be detrimental for some processses: cyanotype sensitizer as well as kallitype and vdbrown (which I never tried, however) should get affected by the sodium chloride which you only need for salt prints. You certainly don't need extra sizing for cyanotype or kallitypes.

No, sizing should be done with a particular purpose/process in mind.

Are you aware that gelatine (other than for salt prints) should be hardened?

 

[Allen Friday]

The Book of Alternative Photographic Processes by Christopher James contains a section on different methods for sizing, including mono bath, two step processes and arrowroot. Seems like a good place to start.

Allen

 

[donbga]

I
I was thinking of making a gelatin mix containing both sodium chloride and citric acid, and I was wondering if using that size would be detrimental to Cyanos and/or Vandykes/Kallitypes..

+ Any suggestions on dosage ?
+ Other ingredients needed ? (hardeners?)
+ Do I dip the paper, or do I "float", or do I coat with a brush ?

Don't waste your sizing paper for any of those processes. Just use a good paper to print on.

Sizing is usually done for processes like caesin or gum arabic.

 

[buze]

Well, I tried a couple of salt prints, and I had quite marked density range in the test wedges at the place where I poured the silver nitrate solution just before I start to brush it over the paper. Which tells me the solution went "deep" almost immediately. That paper had been salted in plain salt solution, no gelatin. That probably dissolved the existing size..

I use Canson drawing paper (the back of) with very good results (to my eye) with cyano & vandyke, but I figured that maybe a "stable" and "known" sizing would help in general.

I also hoped to be able to get better Dmax and longer scale from the vandyke with less exposure... just experimenting really.

 

[donbga]

Well, I tried a couple of salt prints, and I had quite marked density range in the test wedges at the place where I poured the silver nitrate solution just before I start to brush it over the paper. Which tells me the solution went "deep" almost immediately. That paper had been salted in plain salt solution, no gelatin. That probably dissolved the existing size..

I use Canson drawing paper (the back of) with very good results (to my eye) with cyano & vandyke, but I figured that maybe a "stable" and "known" sizing would help in general.

I also hoped to be able to get better Dmax and longer scale from the vandyke with less exposure... just experimenting really.

Canson papers are buffered - use a paper that is better suited to your processes.

 

[zgan]

sizing

Try to find the book Coming into focus, great book covers a lot of techniques

including sizing
good luck Robert