So I'm continuing to make practice blocks and yesterday I got some vellum paper from staples. It is so much better than the simple foundations paper that I linked to in post #98. It is still see-through, stiffer (so more supportive) and yet rips off much more easily. This is the one I got:
http://www.staples.com/Staples-Inkje...product_496755 and I think I'll be sticking with it.
The downside was that when ironing the toner was transferred to my ironing board, so I actually ended up putting a piece of regular copy paper under it to keep the toner off my board. I think if I had used an ink jet instead of a laser, it wouldn't have had that issue.