Hi 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, but I have discovered that sometimes it is better to add the results of my image manipulation as a new channel rather than as a new layer. Any successess I've had so far have been due to experimentation so far though. Can anybody point me to some documentation that explain the differences between the various drawables comprehensively? Thank you for any help! Cathy.