My girls LOVE their Cuddl duds.  I got these to wear under Halloween costumes, but they love to wear them all the time.  I wish I could find more!

The fabric is lightweight, very silky feeling.  The seams are a little ugly, and obviously machine sewn.  We have had some fraying of the seams, but nothing too bad.  My twins wear these for jammies, and around the house, as well as wearing them under clothes for extra warmth.  These are hands down better than other similar undergarments such as long underwear, because these easily go under any other article of clothing with no added bulk!