I have made a weird observation that feels like a bug, unless I am getting something completely wrong here.
I have a document with a white document background and following Layers:
- Bottom layer: White full document size rectangle as background
- Next Layer: Group with following contents: A pixel mask, a photo, a shape
Now here's the weird thing: If you switch the rectangle layers visibility on and off, you see drastic changes to the way the group with the mask in it is being rendered, in terms of contrast and color. This is really confusing me. The white layer underneath shouldn't have any impact, given that all layers are set to normal.
Why does it matter? I like to keep my documents with a transparent background and a white layer that I can switch on/off for export.
I've constructed this simple setup as a demo, the same thing happened to me in a much more complex document and took forever to find out what's going on. The same thing happens in Affinity Publisher.
Is this a bug or can someone tell me what I am getting wrong? Why is this rectangle creating a different rendering of the layer above than the normal white document background?
EDIT: Can't believe I overlooked this: the group layers are automatically set to passthrough instead of normal layer blending mode. Had no idea that this exists and don't really understand what it does, but if I switch it to normal the weird contrast/color distortion by the white rectangle disappears. Anyone have an idea what this mechanism is about?