A long sleeve one piece (also known as a onesie, romper) is an item of clothing for babies that covers the top half of the body and sometimes also the legs. It fastens between the legs over the diaper. Wholesale baby long sleeve onesies are perfect for keeping your baby boys and infant girls comfortable and warm in the winter. Long sleeve one pieces are great gifts. Baby long sleeve onesies are perfect for keeping our newborn baby boys and baby girls cozy, warm and in fashion. Our well manufactured onesies are available in many great colors. 100% Cotton, 65% Polyester - 35% Cotton and 100% Polyester and interlock fabrics are specifically designed for embroidery, screen printing, sublimation printing, heat transfer printing and to personalize. We also have sizes for baby newborns to the baby of 18-24 months. Custom manufacturing available with low minimums and quick turn around.