Sheeting is hard to come by. I wonder if you couldn't make them from regular flat sheets--maybe a size bigger than what your bed takes. Of course if you have a king then there isn't one bigger so you are back to the drawing board

I have made them from sheets before but it does require a lot of fiddling that I thought I could avoid if I could find some kind size width sheeting. But you're right; it's almost impossible to find anything nice. Thanks for your answer.

We've had waterbeds since 1978. I can't suggest a source for sheeting fabrics, but I can suggest this: Use a flat double size sheet for your bottom sheet with sheet garters on the four corners. Then just use a regular queen sheet for the top sheet.

Hub and I went to a regular bed several years ago, but we put a Cal King mattress in our waterbed frame. (For a king size bed use a queen size sheet for the bottom.) I'm still using the same sheet method as I did when it was a waterbed. We still have waterbeds in the kids' old rooms, and that's how I've always done the sheets. They never come off the beds, stay smooth and tight till the next change.

When I worked in a fabric store, we sold an extra wide cotton for sheets - but it was called 'muslin', not 'sheeting'. Perhaps you might try using that term to search?