The other answer is correct. But since you posted this in "Religion & Spirituality", I suspect it isn't what you were looking for. Maybe this is more on the mark: In medieval times the appearance of a caul (veil) on a newborn baby was seen as a sign of good luck. It was considered an omen that the child was destined for greatness. Gathering the caul onto paper was considered an important tradition of childbirth: the midwife would rub a sheet of paper across the baby's head and face, pressing the material of the caul onto the paper. The caul would then be presented to the mother, to be kept as an heirloom. There are many other popular beliefs associated with them, my mother was a "veil baby" and many people in her family believed that was evidence of increased spirituality and psychic ability.