I liked these shirts alot and I got them because I have some reusable Bum Genius diapers that can be worn as pants.  I wanted a shirt instead of a onesie.  These are really nice material, but they ride up and are so small.  They are six months size.  My daughter is not even six months yet.  She was pretty big for them when she turned 4.5 months.  I would recommend buying one size bigger than you want.