The lack of target layers is what I was thinking, and then building the data for each one…prior to painting. I don’t know why Base, R, and G would be required labels for the blueprint portion except that it’s how the code is written. It probably means there’s no placeholder or variable type of naming convention in the code to allow labeling based on attribute (displacement, roughness) or another kind of label. The error could be blocking the paint brush from showing its in-editor form, but that’s a crazy way to handle an error because it portends of something worse than an incorrectly set blueprint or blend material. It’s probably a great idea now to do a few searches for the exact same problem in the forums and in the issue tracker. The issue tracker is accessed via the Learn dropdown at the top navbar under Issues. Not to worry about being all over the place. Problems like that can leave a person scattered at trying to solve a seemingly basic problem.