I'm with auntpiggylpn - just wet the seams and the paper should come off easily.
Like QuiltE, I take the paper off as I complete a block, usually by soaking it in my bathroom sink for just long enough to get it wet. I use thin plain paper though. Try it on one and if the ink doesn't run, you're good to go. If it does use the q-tip/paintbrush method. Under no circumstances would I try doing it in a washing machine.

You can get away without removing the paper and probably be fine. but there are good points about the clumping(having accidently washed paper it does turn into quite a blob)and on a light fabric you may get ink stains. I have used deli wrap as well as phone books for a foundation for strips and found the paper tears off pretty easy. I don't worry about getting every little bit though. they pretty much disolve

If you're having problems getting the paper to come off, shorten your stitch.

For PPing I use the shortest stitch on my machine ... and the paper comes off with hardly an effort on my part.

Paper, yes. Leaving in? No...unless you have a death wish for your washer....

One could try making a pot-holder size "quilt" - just serge the edges - and try washing that a few times to see what would happen.

I'd kind of like to know if the paper clumps up like tissues/kleenex does when I've forgotten to take it out of a pocket - or if it would just sort of turn into lint .

Can't say I'm quite curious enough to actually try it myself, though.

Way back when, people used newspaper for foundation piecing. Wonder if they took the paper off or left it on?

Have the inks and paper processes changed over the years?

I would guess if the item was quilted closely it really wouldn't matter. what little paper was between the quilting lines couldn't go anywhere anyways. If it was tied like a comforter i can see where you could have clumps of paper.

then again my mom and grandma used a wringer washer so any paper left inside would get the snot beat out of it.

I'd be more concerned about my quilt than the washer. Papers are treated with a number of chemicals in the production process - then add the ink - BLECK! I'm not willing to risk my quilt for that.

I have used light weight muslin, it worked beautifully. In fact, one of my favorite throws is a string quilt on muslin with no batting and a heavy flannel backing. It's the perfect weight for me right now - cozy, but not too hot. Things get too danged hot all of a sudden every now and again...

Good Grief YES TAKE THE PAPER OFF!!!!! If you use newspaper it gets dark from the ink in it so imagine what the quilt would look like!! Also I agree with the others who said do it with each square but BE CAREFUL!!! Good luck in your future quilting

first, in the "olden" days, the inks used in newspapers had some lead and other toxic stuff in them. It made the ink not run or rub off on your fingers like it does today. And crinkly may not be conducive to cuddly. Just cause you can, doesn't mean you should 8^)

and since you (and I) compost anyway, what I've done is sit outside on a nice day and pull the papers off and let them land on the grass and compost in that way.

I would not like to use this method unless I removed the paper after completing a section or a block. Like some have said, clumps and ink are not pretty.