Last week I showed off a new creation: a dress made with Cotton + Steel rayon, using a Simplicity pattern to which I added sleeves. Since it’s October and all, I’ll call this technique making Frankensleeves. Today, I’ll show you how to do it.
A sewing beginner might think that you can simply attach the sleeve of one pattern to the armscye (armhole, for noobs) of another without any modifications. A slightly more advanced sewist, on the other hand, might think that when you account for the unique shape of each sleeve and the shoulder slope and the length of the shoulder seam, the whole endeavor is f—ing impossible and life is meaningless and you’d be better off giving up on sewing altogether and living out your days meditating on a deserted island.
Depending on which camp you fall into, I have either some good news or some bad: NEITHER IS TRUE.
Adding a sleeve to a sleeveless bodice (or a differently sleeved bodice) is not as easy as you might think, but Frankensleeves are also not as scary as you might fear. Here’s what you’ll do:
Get your patterns ready.
Find your desired bodice patterns (front and back; we’ll call these Bodice A), your desired sleeve pattern, and…wait for it… the bodice patterns (front and back) that fit your sleeve (Bodice B). So I had my bodice patterns from Simplicity for my dress (A), and then the sleeve and bodice patterns (B) from the Josephine blouse by Made by Rae. I left plenty of room for sketching around my Simplicity bodice patterns, but if your pattern is already cut out you can simply tape it to some Swedish pattern paper.
NOTE: Both sets of bodice pieces should be more or less “assembled.” You want a complete and accurate armhole, from side seam to shoulder seam, on both patterns. If either of your bodices includes yoke pieces, trace all these pieces onto Swedish pattern paper and baste these elements before continuing.

Trace Bodice B armscye onto Bodice A.
Take your desired front Bodice A with the extra area for sketching. Then take the corresponding front Bodice B. Place B over A, lining up the bottom corner of the armscye where the armhole meets the side seam. Our reason for doing this is because this place will be pretty much the same in all patterns, even though shoulder seams and armhole shapes might vary.
Trace Bodice B’s armscye onto the Bodice A pattern, from the side seam to the shoulder seam. In my case, these shapes look vastly different. Bodice A was a sleeveless dress pattern, and the shoulder straps obviously don’t cover the whole shoulder. We’ll address the shoulder seam next.
Draw a new shoulder seam.
Remove Bodice B from the pattern. You should have a new armscye line now, from the side seam to what will be the shoulder seam. Using a ruler, draw a straight line from the top of that new armhole to the neckline of Bodice A, creating a new shoulder seam that is the right length for your sleeve.

Repeat for back.
Repeat steps 2–4 for the back bodice pieces. Now you have a modified bodice pattern with custom armholes for your new sleeves! You have… FRANKENSLEEVES! Follow the instructions from Pattern B for inserting the sleeves, and otherwise follow Pattern A as written.
Garment sewists out there: do you have any additional tips for modifying bodices to add sleeves? Anything I’ve missed?
ErinH
October 20, 2016 at 11:35 am (4 years ago)Thank you for the clear and informative post! I would have been too worried to alter the pattern – however it makes perfect sense when you explain it. Love the pics!
admin
October 24, 2016 at 11:49 am (4 years ago)Thanks, Erin! Let me know how it works out for you.