Could some kind person who knows about Na2 please give me a simple set of 'drop formulas' for the Na2 solutions for palladium printing.... 10%, 5%, 2.5%... mixed from the 20% solution. I am not certain if the formulas are based on weight or volume. So the number of drops of distilled H20 to 20%Na2 for each of the dilutions would be helpful.
You'll need 3 extra bottles. Assuming for the sake of simplicity that you start with 20ml of Na2 at the 20% delivered strength. Put 10 ml of it along with 10ml of distilled water in a spare bottle. That is your 10% solution. Take 10ml of that and add 10ml of water in the next bottle. That is your 5% solution. Take 10ml of the 5% and add 10ml of water. That is your 2.5% solution. You are now done.
Those are the numbers that I came up with, too. I would start out this way until I arrive at a typical contrast level for a print. Then you can make the solutions.
Question:
Does Na2 only work for Pd? Can it be used to modify contrast in Pt, as well? Would this be mixing sodium with potassium - a faux pas on the order of apples and oranges?
Actually, that was three questions.
Most folks use a combination of Pt and Pd for their prints. If you use NA2 you will get Pt salts, because that's what NA2 is. So you will get a mixture of Pt and Pd. I do believe that all these compounds are sodium salts. Don't have the bottles in front of me, so I can't confirm.
There is an article on the Bostick and Sullivan website that explains how to use the NA2 contrast agent. I started using it last year and it works very well. Much better that the "evil #2 solution" as descritbed by Jorge.