Three of the four designs in the Japanese coat book have a back vent. This is my third time around the block so I’ll share what I’ve learned. Hopefully, it will make it easier for anyone either sewing along on this pea coat, or working on another coat with a back vent.
On your pattern, extend the seam line and the fold lines all the way to the hem. Highlight the end points so that you will take note of those areas when cutting the fabric. After cutting, make small clips at those highlighted points. Now you will know exactly where the fabric is to be folded and pressed. This will save you a lot of agony.
The vent “flaps” are then interfaced with 2″ wide strips of crossgrain pocketing. This technique is from the Cabrera tailoring book. Is it necessary? Probably not. But I’d prefer a more substantial vent with some weight to keep it from bumping out. That’s never a very flattering look. The instructions for this coat show a 7 Cm strip of something placed in the hem of the left vent. I’m not sure what it is. Looks like a drapery weight to me. I think I’ll go my own way on this part. Fold and press the vent into position. Then open out the vents and baste the strips up against the folds. The strips are then slipstitched into place. These stitches should not be visible on the right side of the garment.
Fold the vents back over the pocketing and baste them so that they are held in position. The left vent (on the right in this photo since this is the inside of the coat) will be topstitched. Therefore, the hem must be turned up first before the vent is pressed.
This coat is designed with a continuous line of topstitching from neck to vent. I like to baste the entire seam prior to topstitching. This prevents bumps from developing all along the topstitched seam. It also keeps the seam allowance in place underneath everything. I use the presser foot of my 301 as a guide. It’s a two step process. Starting at the bottom I topstitch the vent. I then have to cut the thread, remove the garment from the machine and baste the vents into position. In my estimation one can’t baste this enough. I take the garment back to the machine and pick up topstitching where I left off.
Here’s the finished vent. I’m pleased. It’s hanging nice and flat.