Paper Sizing Formulas

Oxalic Acid for sizing papers for Pt/Pd..... Is the formula for a 1%

solution bases upon weight or volume....... Eg. 1gram of Oxalic Acid

to 100 ml of H20. Is this one shot chemistry or does it have a shelf

life? Is the sizing usually just brushed on or is it immersed in the

solution, if so for how long?

I found other sizings listed that were tested by the

JAIC... "arrowroot, 1.4% (w/v); gelatin, 0.66% (w/v); gum arabic, 15%

(v/v)". Does the w/v indicate grams per 100 ml.?

Actually the entire document is a good read with some detailed test

results if you have not seen it:

http://aic.stanford.edu/jaic/articles/jaic34-01-002_3.html

The link is for the page that relates to my questions.....

Suprisingly, I noticed they are using gelatine with no inhibiting

reactions just a little reduction in contrast....

Thanks in advance...

Greetings,

Oxalic acid is realy not a paper sizing compound. Oxcalic acid is used to make the paper acidic rather than base, which is usually what most art papers are. Any organic acid would work in this application, i.e. citric acid or tartaric acid, though most Pt/Pd printers use oxalic acid.

Gelatin & gum aribic are true sizes for paper and will make the paper less porus. Most papers are internally sized at the factory with gelatin or starch. Even papers that have been sized with these can still be treated with oxalic acid to create an acidic environment.

In your example of 1g to 100ml H2O that would be a 1% solution and is can be resused, it is not one shot. Sorry, but I'm not sure about the w/v.

Regards, Pete