Hi all, This is a 2-part question. Respond to whichever you prefer 1st, I had a solution of 3.5% potassium-dichromate mixed with distilled water. I opened it up this morning (that's right, I woke up early to sensitize!) and it was a cloudy brown sludge. This had been used previously, probably 2 months or more, to sensitize about 10 sheets of 5x7" and put back into the bottle w/o filtering. My "mother" bottle of 5% stock solution is still crystal clear. So, I'm wondering if it is the organic material in the carbon/dye-transfer tissues that caused it to detiorate. - Will filtering through a coffee filter be sufficient to prevent this from happening again? - What is your method for determing exhaustion, replacement, reusing of potassium dichromate sensiziter? 2nd, I am doing something a little different than just typical carbon tissue sensitization, that is, I have gelatin on a clear support (melinex) and I will be exposing through the base so that this support will be the final support for a dye-transfer matrix. This requires that the backside be clean, ergo, I tried brushing on the sensitizer with a foam brush. - I know this is common with spirit sensitiazation, but what about w/ PD? - Is a 1 minute pre-bath still advisable with this method? Thanks in advance for your hallowed wisdom, ye fine carbon printers.