So, uh… looks like I got so caught up in the process of padstitching that I didn’t photo-document the process until I was all the way to the steaming stage! Oh well. There are so many awesome padstitching tutorials online - I highly recommend the video from from Gertie’s Blog for Better Sewing. But yeah, basically, 2-3 evenings of hand sewing to shape the undercollar.
That slightly tight twill tape encourages the collar to flop in exactly the way I want it to flop. Then the little chevron-shaped stitches grab the fabric in small, regular intervals to shape and support it against the hair canvas. As you can see clearly in pic 3 up there, I didn’t do any padstitching within the seam allowance; the excess hair canvas was trimmed away (see the edges in pic 4) to reduce bulk in the seams.
After it was all padstitched, I pinned the collar around a tailor’s ham, arranging it the way I’d like it to lie around my neck. Then I steamed the everliving hell out of it with my iron (applying no pressure - steam clouds only) and left it to dry overnight. The instructions said I should apply fusible interfacing to the upper collar, but I chose not to; that lower layer is so extra, mega supported by the hair canvas that I thought it didn’t need it.