St. Stephen: something amice?

The "collar" to St. Stephen's dalmatic isn't quite a collar; it's another vestment called an amice. All of the amices I've seen have been pretty plain and always white, so I've been wondering what's up with the goldwork and colored thread on his (see the original piece). A good friend of mine was able to explain: in the late 13th/early 14th century, when this piece was worked, the amice was customarily decorated with a band of embroidery. When worn, it would appear somewhat like an upright collar. (This apparelled amice fell out of wide use by the 16th century, but it was preserved in some cases and can occasionally be seen today.)

A casual browse showed me several instances of the apparelled amice in depictions of St. Stephen. The top image for this post, a painting by Giotto, is especially gorgeous. So, our stitched saint has a normal amice after all, at least for the period. I'm happy to know that I can proceed with working it as shown in the original, now that I know why it is depicted the way it is.