step1.JPG (19768 bytes) 1.This is the mockup from Drea's Elizabethan Corset instructions.  I'm going to write to her and ask if we can use the mathematical calculations (not the corset pattern generator, but the instructions on how to do the math and draft it up yourself) for this booklet.  I find that I usually need to adjust the mockup over the hips and under the armpits.
step2.jpg (26368 bytes) 2. I've cut up one half of the mockup into pieces that will correspond to the pieces of the corset.
step3.jpg (121519 bytes) I think if you blow this up you can see where I'm drafting in the lines for boning. If the boning lines don't work out, I can adjust them at this point.  I've also added 1/2" seam allowance to each piece, and added the tabs at the bottom of each piece.  I like my tabs about 2-1/2 inches long, and since I'm using basket caning rather than steel, I want at least three, usually four or five, boning channels per tab.  Otherwise I don't think the tabs will be stiff enough and will break.

Boning channels: I'm using an architect's scale, which conveniently has one edge with markings at 3/8".  I use an architect's square to draw two lines at right angles from each side of the piece.  Then I mark along each line at 3/8" intervals (starting at the edge), until I get to the middle.  You can see the results better in the next picture.  After I have the lines marked in, I figure out the final configuration for the tabs.
step4.jpg (52568 bytes) Here you can see the finished pattern pieces, complete with drafting lines.

For the center back, you can see that the lines are slanted inward, following the side-back edge of the piece, except on either side of the center back, where you need one vertical piece of boning on either side of the lacing holes, for strength.

The shoulder strap is at the top.  It's way too long, deliberately so -- I adjust the length after the whole thing is assembled and I'm ready to sew the leather binding on.
step5.jpg (43799 bytes) Here I've cut out the individual pieces in linen, and have them pinned to the outer material, which is a mustard-colored lightweight wool.  I found that sewing the interior linen canvas to the wool, then cutting around the pieces, is much easier than cutting out all the pieces and then trying to keep all the edges aligned when I sew them.

You can't see it very well from the angle of the camera, but the pieces all pretty much are aligned with the grain of the fabric.
step6.jpg (56101 bytes) Here you can see (right to left) that I'm drawing the boning channels onto the linen, following the layout of my pattern pieces; the first shows the process of drawing in the channels, the second shows all of the channels drawn in.  The third from the right shows (unfortunately, not very clearly) the channels sewn in, using heavy quilting thread or buttonhole thread.  The fourth picture shows the boning being inserted, and at this stage I've also cut between the tabs on this piece.
step7.jpg (33711 bytes) Here you can see all the panels assembled.  I used a zipper foot to get the needle right up to the boning channels. 

I ironed the seam allowances and tacked them down with a whip stitch.

At this point, you would attach the lining material (not shown) -- you could pin it to the edges and tack it in place with a whipstitch.

 
step8.jpg (39509 bytes) This is the front of the stays at this point.

Kass wanted it to lace in the back only, but I put three boning channels in on each of the center front panels, so if she changes her mind later, she can un-stitch the center seam and remove the boning from the second channel on each piece, and add lacing holes.
step9.jpg (66993 bytes) This shows the binding partly applied, and the eyelets have been sewn in.  I sewed the eyelets in first, then adjusted the length of the shoulder straps.

Then I put the binding on the center back and top edges with the sewing machine, sewed it to the right side of the stays and then folded it over to the wrong side and tacked it down with a whip stitch.  This is the tough part -- you need a thimble, and it helps to work the leather wet, as that makes it more pliable and easier to punch the needle through.

You can see I've also sewn the binding onto the lower edge with the machine where possible.  I had to sew the binding onto the tabs by hand, as they're too fiddly to do with the machine.  I've managed to do the tabs with a machine before, but I just had trouble with this set... not sure why.
When Kass sends me a picture of the finished product, I'll send it along :D