I've not tried it yet. We've got a little here that we use to stake out plants and things. I think it would work well for placemats or whatever, you'd probably have to block it though.
I haven't checked prices yet but Wal-mart carries hemp twine in the hardware department.
I'm hoping to frog and redo square #12 today. I should have gone up a hook and I didn't pay close enough attention. I'm probably a row or two from finishing it now, but it's all got to go.
Maybe I'll have pictures of squares later today.