Wadding, defined: little balls of refractory clay that keep pots from fusing to the kiln shelf. This pottery t-shirt names a wood firing and salt firing essential for ceramic artists who know the old ways. Atmospheric firing fans will love it as a nerdy ceramics gift. 100% ring-spun cotton (heather colors are cotton/poly blends; Sport Grey is 90/10) Lightweight 4.5 oz Gildan Softstyle® 64000 that feels broken-in from day one Classic unisex fit with a clean crew neckline No side seams and twill-taped shoulders for a smoother drape Ribbed-knit collar that resists curling, plus a soft tear-away label with no scratchy tags OEKO-TEX® certified and made with ethically grown US cotton Note: due to fabric properties, print colors may appear slightly different on white or light garments.