I've only done it twice. The other beinghttp://www.pbase.com/image/4369293 Don't even know if I remember how now. For these, two exact same frames were needed. One with an r72 IR filter on the camera & one done in normal color with no filter. Then layer one on top of the other & using the eraser in an editor to remove the top layer exposing the bottom layer. I'd suggest having a tablet instead of a mouse. I wouldn't have even tried with anything other than the tablet....