A better paper and readily available is butter paper, the paper that sticks of butter come in. It is really tough stuff.
My friend, the serious BP tournament shooter, turned me onto it when I mentioned finding some onion paper to patch some conicals and try to get them to shoot in my round ball .40 barrel.
Onion paper didn't work for me or my friends shooting conicals, butter paper gave them some pretty good groups at 50 yards, minute of deer anyway. I haven't tried the butter paper in my rifle yet.
If you want to try onion paper, you can buy just a few sheets off eBay for a couple bucks shipped.