Durer, circa 1505: Portrait of a Venetian Lady.
image shows a close up of the fabric caul, which appears
to be made from a fine, sheer fabric - probably silk. It
also appears that the silk fabric is patterned or
textured, and there is a firm edge to it, which may be
either a rolled hem, or a tiny casing for a draw cord,
but this is simply a theory.
The hair underneath appears to be braided, and the
ends of the braid fastened at the top of the head. The
caul is then put on over, and the braid provides a solid
surface to rest against, which helps it to stay on the
head. It is not clear how the caul is fastened, but it
may be tied either under the chin (as previously the
scuffia/cap was) or behind the head. No ties are visible,
however, so this is uncertain.