My print paste experiment has been in place for three months. My theory was that the Print Mix from ProChem had additional ingredients that gave the paste a longer shelf life than print paste made from scratch with sodium alginate and urea.
I had been checking the paste weekly until a month ago. There wasn't much to report at that time. Both the print paste made from scratch and the one made from ProChem's
print paste mix were about the same consistency. However both were
thinner than when I started. When I checked the paste yesterday, there was a noticeable difference. The print paste made from sodium alginate was much thinner than the ProChem mix. It was still usable, but definitely on the decline.
The results weren't as dramatic as I expected. I did the experiment because it seemed like my print paste (made from scratch, not Print Mix) went bad very quickly - within 3 weeks. Yet, this batch lasted for three months. So now I'm not sure if it's a time perception issue, or if my real-life approach of leaving the print paste out of the fridge for a few days after using affects the shelf-life. If I really want to know, I guess that means another experiment!