Seamless Rib Onesie Seamless Rib Onesie Black Cotton On Bottoms Superbalist.com SKIMS Gray Cotton Rib Onesie SKIMS Ribbed Onesie Bowy Made. Baby boys and baby girls stripped ribbed onesie with envelop shoulders, center back snap opening and elastic at back ankle. Available in the following colors: Dark Mauve Pine Green Cocoa Composition: 72% Polyester 20% Rayon 8% spandex Knit Washing Instructions: HAND WASH COLD, INSIDE OUT, NO CHLORINE BLEACH, LAY FLAT TO DRY