I decided to pull my old bottle (two years approximately) of Emerald out of the cabinet and make a print with it, but found that due to age, handling, etc., the concentration of pigment and/or UV inhibitors is higher than normal, requiring significantly longer cure times compared to my old profiles (note: non-B9 printer). I did manage to get a print that looks good, but I had to triple my standard layer exposure time. Other resins in my possession have not changed in their behavior, so I don't think the projector bulb is the culprit.
I've read that you can try to decrease the pigment by allowing the resin to separate, skim off the non-pigmented liquid, then slowly add pigment back into the mix to get the desired behavior. One of the great things about Emerald is that it takes a very long time for it to separate, which makes this method very painful.
Is there a way to 'thin' the resin using generic monomer, or one preferably compatible with the monomers used in Emerald to try to get the cure times back in line with the original specification?