CALCULATING PAPER DRY DOWN -

It's really quite simple to determine how much each manufacturers paper will darken when dry. It just takes a single printing session, a calculator and a note book.

1 - Make what you think is a final print and leave it in a holding tray of water after fixing.

2 - Next make a series of 6 additional prints, but with each print remove 2 % of the previous exposure. (If the original prints exposure was 20 seconds, then you will have a set of prints at 20 secs, 19.6 secs.,19.2 secs.,18.8 secs., 18.4 secs.,18 secs. & 17.6 secs.) Be sure to mark the percentage difference (2%,4%,6%,etc.) from the original print on the back of each print in pencil before processing and process these prints using the exact same development time and agitation as the first print.

3 - You will now have 7 prints in the holding tray. Wash the 19.6 through 17.6 second prints thoroughly, dry and flatten. The original print should be left in the wash tray.

4 - Take the dried prints back into the darkroom and one at a time compare them to the still wet original. Which ever print comes closest to matching the still wet print represents the dry down percentage of that paper. Make a note of this percentage.

5 - In the future, when using this paper, after you have gotten what you believe to be your best possible print and after inspecting it in the fixer or wash, make another print by removing this percentage from the total exposure. This print will dry to the print you see in the wash tray.

6 - A few additional final notes on dry down - Some printers take the test a step further and selenium tone the percentage prints before comparing them to the original. This is something that I recommend, as selenium toner will darken the blacks in a print.

• You will find that different manufacturers papers and different contrasts of the same paper dry down at different percentages. This test should be run with each paper you use.
  

• When inspecting the percentage prints, pay close attention to the shadow and highlight areas. This is where you will most easily see the dry down effect.
  

• If you find that the dry down seems to fall between two of your percentage prints, (e.g. say between 6 & 8%) run another print at that in between time (e.g. 7%) to calculate the actual dry down percentage.