I've formulated 2.5 liters of two solutions D-85 (kodak lith developer). I don't find Paraformaldehyde and i've replaced it with around 200ml of acetone (82.5 mm x 2.5) but the solution DON'T WORK! For a test, i've mixed 4 parts of solution A with 1 part of solution B (no water) and i've make a strip test with 2 min, 4 min, 6 min, 8 min and 10 min. exposure time. I've immersed the strip into solution and after *10* minutes the strip test was always white (no halo, no shadows) How can be happened? Sorry, have patience, a second question: What is life time of FX-37? My formulation have now 4 mounths. thanks to all and sorry for my english! PG