Quote Originally Posted by Troy
Hi there,

Sizing advice: First check to see if your paper already has sizing. Many high quality watercolor papers do. If so, this is generally enough. Van Dykes and Kallitypes definitely need sizing. Arrowroot is a very, very safe sizing. They make cookies for babies out of it. But it's not the most effective method. Better choices are gelatin, gesso or gum arabic. Get Christopher James' book "The Book of Alternative Photographic Processes" for the skinny on everything you want to know and more.
Troy,

I have to disagree with you about the sizing for Stonehenge. You can print VDB and kallitypes just fine with that paper without sizing. C. James book is quite informative but not always accurate. But if you want to size you can but that will change the printing characteristics of the paper. Arrowroot will create warmer tones than gelatin sizing. In general I avoid papers that require sizing for iron based processes, it's just an unecessary nuisance.

As for Martin's question about printing times: If step one of the step tablet has the same density as the uncovered coated areas and has not merged with step 2 then the base printing time has been determined. However the actual time for printing negatives will be longer since adequate exposure for film base plus fog needs to be accounted for. Not to mention the need to evaluate how the shadow areas print detail.

In alt processes we print for the dark tones and adjust contrast for the highlights, just the opposite of silver gelatin.

Quote Originally Posted by menglert
I think if I shorten the time it will help be build better curves from the step tablet and have my middle values more centered.
Sounds like you are testing for digital negatives? If so then perhaps we should continue this discussion in the Gray area.

Don Bryant




As for