毫毛或称胎毛是一种只有婴儿才有的体毛，它的功能与头发类似，但在婴孩八个月时就会逐渐消失，由于有此总特处，故有家长把孩子带到可订造毛笔的地方，把毛刮下制成毛笔作为送给孩子的独特礼物。

• 胎毛笔

Lanugo (/ləˈnuːɡoʊ, -ˈnjuː-/; from Latin lana "wool") is very fine, soft, usually unpigmented, downy hair that is sometimes found on the body of a fetus or newborn baby. It is the first hair to be produced by the fetal hair follicles, and it usually appears at about five months of gestation. It is normally shed before birth, around seven or eight months of gestation, but is sometimes present at birth. It disappears on its own within a few days or weeks.