In preparation for making your Simplicity 8162 18th c. stays, you may wish to re-draw the boning pattern.
The pattern comes with an accurate layout for half-boned stays. If you would like to deviate from this, perhaps to add more support or change to a fully boned stays pattern, it's a very easy alteration.
All you need to do is redraw the boning channels. On my stays I've done fully boned and simply drew the pattern I wanted on the interlining layer. It's as easy as that.
On your stays pattern there are "no go zones" where your CF and CB needs to have channels on the edge and opposite side of the lacing holes. You'll notice in all the patterns I've drawn out that this "bone-grommets-bone" pattern is on the front and back pieces. Other "no go zones" are the seam allowances - obviously you don't want to run your boning channels into the seam allowances. I typically will do one channel right along the seam on either side, parallel to the seam.
Drawing the Pattern
After you've marked out your CF and CB "no go zones" and your seam allowance, you can draw whatever pattern you like. Keep your references handy and pay attention to how the boning channels intersect the tabs or curve across the body.
3/8" channel for 1/4" wide zip ties
5/8" channel for 1/2" wide zip ties
Here are several boning patterns from original stays, in chronological order:
On many of these layouts you will notice horizontal boning across the bust. This creates more support for the bust, especially larger busts. But how do you stitch this in?
The answer is to create a "pocket," a separate piece that is applied to the bust area after the vertical boning channels have been stitched into the outer fabric and interlining. I make my pockets of two thin layers of muslin with the horizontal boning channels sewn in, then I tack the entire piece to the interior of the stays.
You can stitch through all layers to secure it, but I usually just secure the pocket to the seam allowance and top edged. Another method for horizontal boning is to stitch linen or cotton tape to the interior to create individual channels. With any of these methods, if you stitch through all layers, be sure to sew the pocket or tapes in *after* you've inserted the vertical boning, so you don't accidentally sew the channels shut!
Once all the boning channels and pockets are sewn in, the interior will be covered with the lining, so don't worry about it looking messy!
Boning channels can be quite creative. Keep your references handy, but don't be a "slave" to the reference. Think about how different boning directions might affect your body, and don't be afraid to experiment.