Pros : Shelf paper is faster to use than kiln wash.
You can cut large rolls to fit your shelf or slump form and use just what you need as you need it and not waste any.
Cons : Forget the reviews from years ago saying it lasts multiple firings, Now it doesn't even work for a single run without flaking and getting fibers stuck in my larger pieces. Smaller globs and dots will rip the paper just from the glass edges moving to ball stage. Even small and medium pieces without fibers stuck to them end up with very rough and uneven backs,
On top of, I have to test another shelf paper brand to be sure, but I've been seeing a LOT more devitrification, esp in the opaque glasses and I'm afraid it's the papyros off gassing and triggering it.
Other Thoughts : When I first got my kiln, it was second hand and came with Papyros sheets that had been pre-cut to fit that shelf, I could use those 2 or even up to 4 times if I was very careful. When I started running low, my local store only carried bullseye so I bought that, and it was nice, but expensive so when they closed I figured it'd make sense to buy a nice big roll of cheaper Papyros that I could cut to the correct size, save $$ and not have weird random sheet edges left over. I cut several pieces for my kiln so they could relax, as it was VERY stiff and the roll is so big that my workshop doesn't have space to leave it out.
I calculated I could get 66+ sheets and figured that would be around 100 to 150 firings, but after I used it, I almost can't stand that it will take 66 firings to use up, and if it is the de-vit cause, I will have to toss the whole thing.
I made the mistake of buying in bulk to save money and now it may all be a waste. :(