The fitted sheet fits very well on the mattress of our 100 x 100 playpen. However, I find the material a bit thin, so you can see shining through the inscription of the mattress. As a heavier thick quality I would have preferred. Also, I must criticize the fact that a red and a green small stain on the bed sheets are where seemingly discolored thread was woven. But since it's so small and therefore unremarkable, I have not returned the sheets.
