Are impossible to find! I can't find decent ones anywhere! Carters doesn't make them in 9 months. Gerber makes 6-9 but theirs run incredibly small as does Spasilk. I don't understand! I need them to put under onsies to keep baby warm! What do people use these days in winter? Am I missing something!
Re: Side snap 9 months
ETA and do you mean under sleepers/ sleep and plays?
ETA: sorry. I re-read. Do you mean you put a snide-snap shirt under a onesie? I don't think most people do. I think most people use them for during umbilical cord healing and as actual shirts.
For keeping baby warm you can get thermal underwear from the gap to go under the clothes. I also use the outfits from the Carter's polar fleece line. They are layered sets. They also have the one pieces.