... Here there are 3 overlapped disks. The disks are are pure Red, Green, Blue, and created using "additive" mode (in PSP 9, but most 2D software will allow you to do this). (Note - they MUST be on a black background!) By using the "Math->Component" node, it's possible to extract JUST the individual bits.. So you can combine 3 masks in a single image:-)) (Feel free to get as creative as you want.....) Cheers, Diolma