1) Right now my favorite is Carol Doak's paper. You can order some from her website at
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. I bought a ton of it from an online shop that was going out of business.
2) The other paper I have used is from That Patchwork Place. I had trouble finding it again when I ran out.
3) I have cut down 9x12 newsprint from children's drawing tablets. It's a lot heavier than the specially-made paper, but it works.
4) In desperation I have used 20lb copy paper. Not a good idea but OK for truly desperate circumstances. I wouldn't use it for pieces with really spiky points or with small pieces. It is harder than the others to remove.
A friend of mine uses vellum from the over-priced LQS. There is a fabric foundation that JoAnn's sells. It DOES NOT tear out. I'd use copy paper before I used either of those.
Whatever you use, it has to go nicely through your printer.