K--I know you have yours done, but here's another option I would like to give. There is a product called Triangles on a Roll and comes in 11 sizes. I think it is like Tada but it tears off like thangles. It is pretty thin so is pretty easy to tear off. They also have grids for other triangles. Here is a link:
http://www.trianglesonaroll.com/halfsquare.aspx