Using PS 7 and a trackball, I'm having a terrible time controlling the patch shape. I can handle many of the other detail functions, but the patch shape wobbles around. I don't see any aids like holding down shift.

Let's say I have a photo of a striped couch with an armadillo on it. I want to remove the armadillo by patching the striped pattern over the beast. The patch has to be pretty precise because of the stripes. Any suggestions?

I really don't have a picture of a striped couch with an armadillo, but it could happen, right?