I have a problem in GIMP with the opacity of a layer. When I change the opacity of a layer(e.g opacity is 40) and go to another layer, the previous one's opacity goes automatically to 0. Does someone knows how can I fix this problem? Thanks!
If it is a color-indexed image (typically, loaded from GIF), then this could be expected, since GIF doesn't support partial opacity, so in color-indexed mode pixels are either fully opaque or fully transparent. Convert the image to RGB (
Image>Mode>RGB) to avoid this, but if you export to GIF again you may not get what you expect.