Quote Originally Posted by scootermm
the really interesting thing I learn jim...
when I would tone one 7x17 with the 10 drops for 20mins. Then Id put another 7x17 VDB in toner bath. even after 20 mins. there seemed to be no discernable difference. SO I deduced, in my finite empirical science mind, that the pt had been completely replaced in the VDB. so it seemed a good economical and effective way to use just enough metal solution without wasting. hope that made sense.
It may have been that all the pt was used, but it may have also been a pH issue. There is a pt intensifacation step for PT/PD printing where you use platinic acid and sodium formate. There need to be a precise range for that toner to work. If the pH os too high or low it is a no go. You may wish to try it again but prior to placing your print in the toner directly try a acid bath only, then put it in the toner. With all the buffering that goes into paper and the alkaline level of some water, that may be an issue for you.