03-28-2018, 05:57 AM
(03-27-2018, 04:01 PM)rich2005 Wrote: For Gimp 2.8.x a layer mask created from either a selection or a channel for each layer is about as fast as anything.
Careful with that, it depends a bit what the layer modes are. If mode is Normal then fine. Otherwise, since the blend is factorized by the opacity, the effect of the partially opaque edge pixels of the top layers isn't the same. However, in that case the final opacity of pixels is the one of the bottom layer, so you don't need a mask on the top ones.