From the clever duo Rebecca Dolen and Brandy Fedoruk of Regional Assembly of Text, a card that also delivers a trio of cute pins they can wear (or just admire,) one of them definitely onesie-ready. 

Single card
Removable, wearable button pins
Blank inside
White envelope
Card 4.25 x 5.5" folded
Buttons 1.25" and .875" diameter