millinery buckram is different from bookbinding buckram. the former is impregnated with a starch which allows it to be softened in water, pulled over a hat block, and left to dry into a hard shape. millinery buckram comes in many weights, including lightweight or baby buckram (often used for children's and dolls' hats), single-ply buckram, and double buckram (also known as "theatrical buckram" or "crown buckram").