I always remove the mirror when I have to refinish the frame, just so I can get the inside lip of the frame. But sometimes, when the picture frame is huge, custom and the back looks all nice and pretty like, I feel bad taking it all apart, knowing the customer payed good money to have this done at one point. Not to mention I really don't feel like removing or replacing 800 staples.
1- bring the tape over the edge
I have found a PERFECT way of dealing with those corners! I hope these pictures below will help explain the steps for you.
2- fold at a 90 degree angle, keeping it tight to the edge and tucked as close as possible.
3- press tight and close to edge, keeping a razor blade nearby to help
4- Perfect, tight corner and super fast!
Awww. Peter deserves an award for putting up with the daily "deep love and serious affection (aka...torture) he gets from my youngest. Tonight he was a lion with a the fur off of someones coat wrapped around his neck. Doesn't he look happy!