We get quite a few "OMG this is the best product ever" posts. This is mine.
In this post
(Less than 40$US.)
This is a PUL backed quilted cotton pad that fits across the bed on top of the sheet with wings that tuck in under the mattress on both sides. The key thing is that it goes on top of the sheet, not under it. So if you leak the sheet stays dry.
I've been using a length of rubberized flannel sheeting with a beach towel on top (for absorbancy) to do much the same thing. This is not only better---much much better---it's cheaper.
It's comfortable to sleep on. It stays in place. It holds (they say) up to 2l (over an 8 hour period). It washes in the washing machine and dries in the dryer on low heat. Fast. (The rubberized flannel can't be put in the dryer and takes forever to dry.)
And it makes me happy. What could be better than that?