Info for those using water washable resin. I had been using what was locally available from Microcenter which is eSun and Inland. The results were brittle parts that limited me to what I could print, so I decided to try something else, and while searching I came across a result for Phrozen water washable model gray resin. It was touted as non-brittle so I bought a bottle.
The result was great. I was finally able to print a pulley and belt setup that I designed for my Ardun head flathead engine and finally had success. the thin belt section was pliable enough that I was able to cut the support from it and not break the belt. I could see the flex in the part, but it didn't break as it had before. The pic below shows the Sun and Inland resin usually resulted. The pic is in white resin but I also tried grey but I didn't save any for pics. The second pic shows the assembly on the engine.
So although water washable resin is overall more brittle than alcohol washable resin, there are differences between water washable products.