I have two of these and just bought two more for our baby girl. They are PERFECT for sleeping, it is not very thick material, but VERY soft and comfortable, no annoying tags inside to bother baby. My husband and I both love that we don't have to struggle getting this over her head as it snaps closed kimono style, a definite plus. I wash & dry them along with all my other baby clothes, they shrink a little, but have held up well. LOVE THIS design.