Windsor Newton Artist's Re-touch varnish, actually. I'm in my last week of prep work for a show and was applying retouch varnish to my paintings earlier tonight. I noticed a few paintings (about five I think) were resisting the retouch in some areas. It's very strange, like the retouch will not coat certain spots. It brushes on, then crawls back. The spots are very small but still very noticable, especially if it's all over the painting. I can't figure out why this is happening. One affected painting has been sitting untouched and drying for some months, so it can't be that the paint is too wet. I've never experienced this before and can't figure out how to fix it. Recoating once the first layer is dry doesn't seem to do any good. I've also tried a new bottle of retouch, same problem.
Anybody have any ideas?