Hi, Cathy Irwin <ctn@xxxxxxxxxxxxxx> writes: > I am a relatively new user of the GIMP and am experimenting with > writing my own plug-ins. I am still having trouble working out when > it is most appropriate to use layers and when to use channels. I > understand that channels are to do with RGBA values. You have misunderstood the concept of channels then. Channels are saved selection masks. They consist of what could be seen as grayscale data and are used to store the selection. The top three or four "channels" that you see in the Channels tab in the user interface aren't really channels. They just appear there for historical reasons. Perhaps because Photoshop puts them there as well... Sven
