Below are some interesting pictures of embroidery work in the liturgical vestments of the Order of the Golden Fleece, dated c 1425-1440, from Burgundy. The vestments have a lot of beautiful, detailed figures with elaborate clothing, but I found these two very interesting because the darker stripes at the front of the female Saints dresses look like they migth portray seam lines. If those are indeed seam lines, they are placed exactly in the way that would be called "The princess cut" today. Usually late medieval dresses seem to be cut in four panels with a center front and center back seam, though the Greenland gowns do have more shaping seams. In these pictures, however, the seams lines seem extremely modern, and would be able to give a very close fit for a curvaceous body that is harder to get with the four panel cut.

I have not researched the period very much, but these two figures caught my attention. If anyone knows more about the subject, or knows of other sources which indicate the possibility of princess cut in the 15th century I would be very interested to learn more.