Why are waterbed comforters sometimes different sizes from conventional comforters?
Waterbed comforters are usually tucked between the wood frame and the waterbed mattress. Since they only tuck in a few inches, they don’t need to be as large as a comforter that “drapes” over a conventional bed. Some people though, prefer to “drape” their comforter over the sides of the frame, and may opt for a larger size to have this feature. Always measure your bed and compare to the given measurements to be sure you are getting what you want.