Professionally screen printed on white lap tees with black ink. 100% cotton. Children's sizes 2, 4, 6 are printed on a poly blend white t-shirt. Please see our other listing for the natural/cream colored organic children's tee, in our children's section. Sizing recommendation: size up by one for the infant sizes. For children's sizes, size two can fit children ages 1-3, size four can fit children ages 3-5, and so on and so forth.