After much fear and trepidation, I have finally succeeded in sewing a vent extension without a hitch.
I sewed a dress from a pattern I drafted recently where the vent had to become a “design feature” to put it nicely, because the thing ended up like a box pleat. And the lining? Yes, it was put in as a box pleat in the back as well. Oh, the horror. To think that a lady who has sewn her own wedding gown that turned out magnificently had botched such a “beginner” skill. Guess what? It’s not! Vent extensions were not commonly used in household sewing until the 1930’s! Therefore, worry not, you can learn to sew a vent extension if you haven’t done one yet or have been reluctant to start sewing that pencil skirt because there is a vent in the back. It is scary, but it exists, so there must be a way to make it happen!
Take charge and watch these videos before you begin! Then, I shall explain the niceties of the vent.
FashionSewingBlogTV: Sewing lining to a Vent: https://www.youtube.com/watch?v=EV6dNTi6WvU
Sewing a vent: https://www.youtube.com/watch?v=rLzya7hRUXY
ProfessorPincushion: How to sew a Back Slit or Vent Extension: https://www.youtube.com/watch?v=66aq038eP5Y
Here are some things about sewing a vent that I figured out:
1) Do not finish edges of fashion fabric or lining when putting lining into dress. Do it later. The seams will be hidden by the lining anyway…
2) Work on the back of the dress/skirt first before sewing any side seams because it makes the process so much easier!
3) Some patterns have the curved underlap like Colleen shows in her video. Cut out the pieces as they are shown in your pattern for best results. I cut mine out both the same.
4) Fashion Fabric: You can baste the vent extension, clip the TOP LAYER and then press it to the RIGHT
Then, you will do the same thing with the lining but press to the LEFT. Then TAKE OUT basting!
5) DO NOT SEW THE LINING VENT EXTENSION! Only sew the vent extension on the fashion fabric.
6) The DOT is all-powerful. Pay attention to the DOT. You will need it for EVERYTHING, so make sure you mark the DOT on the fashion and lining fabric on the wrong side of ALL PIECES.
7) The seam you will sew that encases the lining in the fashion fabric is ¼”, so you will need to stop sewing the vent extension on the fashion fabric ¼” from the edge. Don’t backstitch it so you can open up the seam edge and finagle it if needed.
Steps to sewing a vent:
1) Take the back pieces of your pattern, sew in the darts and staystitch neckline and armholes.
2) Line up the zipper you are using and decide if you are sewing an invisible zipper, All Purpose zipper, or a LAPPED zipper. Mark where the zip ends on fashion and lining fabric.
3) Baste the 5/8” Seam allowance for the zipper from start to end. (Length 4, Tension 1-2)
4) Stitch the area from end of zipper to the DOT with normal stitch (Length 2, Tension 3)
5) Baste the area from DOT to HEM (Length 4, Tension 1-2) You may need to draw a straight line to make sure you sew with the same seam allowance throughout.
6) On the FASHION FABRIC ONLY, stitch the VENT EXTENSION, or the part that slants DOWN away from the main body of the dress back. Make sure to stop stitching ¼” from the edge!
7) CLIP the TOP layer of the seam allowance diagonal from the DOT, being very careful not to cut the stitching! A little notch will suffice. Do the same with the lining, even though you didn’t sew the vent extension yet.
8) Fold the fashion fabric vent to the RIGHT and the lining fabric vent to the LEFT. Press along the basted line, then REMOVE BASTING from DOT to HEM.
9) The name of the game now is to stay AWAY from the DOT. Do not catch it in your stitching for the next few steps.
10) Take the TOP EDGES of the fashion fabric and the lining and match up the RIGHT SIDES, and pin along the edge. Get ALL excess fabric out of the way to avoid catching it. LOOK at the stitching of the vent extension on the fashion fabric. Line up your presser foot on the edge of the fabric for a ¼” seam. Manually turn the wheel while holding the threads. Go forward 3 stitches, back 3, then forward 3 again, then stitch down the line with the pedal.
11) Take out the pins and trim threads, then do the same to the other side, but pin so that the seam is sewn from the hem to the DOT. Fashion fabric should be facing you again. Don’t catch excess fabric.
12) Take out pins, trim threads, tack anywhere the stitching may be loose. The edges should line up perfectly in a little square between fashion fabric and lining.
13) The Lining vent extension is not sewn yet. Put a pin in the DOT to avoid catching it. Then put 2 pins in the vent extension and line up the presser foot for a ¼” seam. Manually turn the wheel, backstitch, sew forward all the way to the edge without catching the fashion fabric, backstitch.
14) Take out pins, Clip the lining on the other DOT edge, being careful not to trim the stitching line.
15) The vent extension should now look like a V. Pull the lining up and look at the fashion fabric from the right side. The edges of the vent extension should overlap, Left over right. It should look perfect. Now you can decide whether you want to topstitch the vent extension. I chose not to because it looks nice and smooth just as it is. I may put in some invisible stitches to tack it down with white thread.
16) BREATHE and PRESS the vent. YOU DID IT!!!
17) Sew the side seams of the dress and lining, then put the lining into the dress!
18) Viola! A lovely, professionally finished dress!