Whether adding to, or subtracting from, a seam your newly drafted lines should always blend smoothly into the existing seam line. If you are using the post Edwardian pattern you are done. Cut out your pieces and relax. Those of us using the Corsets and Crinolines pattern have one more step, adjusting the center back length, which I will explain tomorrow. Until then, take pride in your fabulous pattern drafting!
January 18, 2012
1911 - transferring alterations to the pattern
Once you've sewn and fit a mock-up you've already used all of the skills needed to make the a finished corset, drafting, tracing, cutting, sewing, grommet setting, and fitting. For the rest of the sew along we'll just be building on and refining those skills. Yea.
So the fit works, now it's time to transfer the changes to the pattern. You will need paper, tape, pencil, a ruler, a tape measure, a hip curve, and scissors or a exacto knife.
First, if you added seam allowance to the top of the pattern when tracing and you want the additional height you must add that to the pattern. Everyone using the Corsets and Crinolines should keep that inch because we'll add to the top of the center back so we can use the 16 1/2 inch bones at at the center back. I'll explain this in more detail later, but for now start by taping the pattern to a piece of paper and draft the higher edge 1 inch from the pattern, the same way you added the seam allowance.
Use the hip curve to extend the seam lines so they reach the new top edge.
You should easily be able to see how much you altered each seam by measuring the fabric. There should be a line at the patterned seam 1 inch from the edge of the seam allowance, just measure the distance measure the distance to the alteration you sewed. Often when fitting the seams they may not have been altered the exact same amount. Say the first seam on the right side was taken in 1/4 inch, and the first seam on left side was take in 1/2. Split the difference. So the alteration will be 3/8. Remember that 3/8 taken in on a seam means that 3/8 must be taken off of each pattern piece that joins to make that seam. If you have been sewing for a while this is obvious, but if you are new to patterning and construction it isn't, and it's frustrating to sew up a corset and figure this out when it doesn't fit. So learn from my mistakes and make the change to both connecting pieces.
Go to the pattern and mark the alteration. For example, I let out the fabric 1/4 inch on the seam at the underbust line. So I'll measure 1/4 off the top edge of the pattern piece.
The new seam line is drafted so it blends to the waist using a hip curve.
Then I do the same thing to the other pattern piece. If you made large alterations you should measure and true your seams again, but for most any change won't be significant. You can see here the difference was just 1/8 of an inch. You can also see I scribbled out the old seam line so I don't accidentally measure or cut it.
If you need to reduce a seam mark the adjustment, draft the new line using the hip curve, and cut off the excess.