I did not find a direct answer searching for this, so perhaps someone can clarify. I have two layers, A and B, on which the same image has been brushed into an intricate prior Fuzzy selection obtained from a bitmap image on a 3rd layer. Layer A is pure black. Layer B is 273d2d green. The unpainted areas of these layers are Alpha Layer. I am cleaning up some "over-spray" as the selection had been done using the Fuzzy Select tool, and here and there it got overly aggressive and "leaked out" into undesired areas. Easily remedied with careful inspection and the Eraser tool. But I have to erase the unwanted pixels in a spot on layer A, then switch to layer B and do the same spot, because I don't yet know of a better way. But I see the little chain icons on these layers in the Layer dialog. And although trying to find how to do what I want in the manuals has not resulted in telling me what I need to know (I probably don't know what terms to search for) I am guessing there is a way to tie multiple layers together and have what the eraser removes on layer A also get removed on layer B. Or, when I am painting the original selection on Layer A, I could possibly also paint the same color simultaneously on Layer B (when required) instead of doing them one at a time during that step of the project. So, how does one join two layers to make this happen? I tried clicking the chain icon on both layers, but what I erased on layer A did not get erased on layer B.