I'm sure they'll work. But if you already have a basic understanding of the concept, it seems like a lot of extra work.
If you just took the sheet and slapped it on the fabric, fine.
But you have to measure the distance and cut the paper.
I think it's just as easy to draw a line yourself.
Or use the Angler2 thingie. I really like that notion.
http://www.pambonodesigns.com/SuperS...ProductID=1084