DuPont 55-D Standard Paper Developer: (4 lb can) DuPont 55-D is prepared especially for use with Velour Black and other similar photographic projection papers.

From back of can: "Open top of can with a puncture-type opener. (Do not use rotary-type can opener) Completely dissolve contents of top in 15 quarts or 14 liters of water at 125 degrees F (52C). Next, puncture BOTTOM of can and slowly add contents to first solution, stirring until completely dissolved. Add water to make 5 gallons (18.9 liters) of stock solution. For use, dilute one part stock solution with two parts water. Develop prints for 1.5 to 2.5 minutes at 68 degrees F (20C). For warmer tones, add 5 to 13 grams of potassium bromide per quart of stock solution. When potassium bromide is added, increase exposure and shorten development to 1.25 minutes."

Note: I have 18 cans of this developer.