A reader asked “On a commercial pattern I have decreased the size of my armhole on a blouse pattern. I took 1 inch out of the front armhole. How do I adjust the sleeve pattern?”
I assumed the problem was a gaping armhole – too much fabric above the bust area. This usually occurs when the shoulders are narrow and the bust full.
I checked all my books and this is what I found out:
For a small adjustment, padding could be added to the shoulder to lift the armhole while making the shoulders appear less narrow. This method would be a particularly good solution for heavier garments like coats and jackets. You could use larger shoulder padding for larger adjustments you just want it to retain a natural, well-balanced, body shape.
When adjusting commercial patterns remember the outside line is the cutting line, not the seam line. To get it out of my way, I cut the seam allowance off in the area I need to make alterations to. At the least, I draw in the seam line. No need making adjustments to seam allowance and it gets in the way when you need to true or redraft the seam line. After making the adjustments I add seam allowance back by taping strips of tissue paper on the edge of my adjusted pattern and drawing the seam allowance on. Or you could add it back on when you cut the pattern out.
There are two ways to take out the excess fabric from the bodice front pattern. The first one listed is for taking out ¾” (2 cm) or less from the front of the bodice and the second method is for an adjustment larger than ¾” (2 cm). How to adjust their sleeve patterns follows.
For a minor adjustment take out the excess from the shoulder by lowering the shoulder seam line on the front bodice only. Lower the shoulder seam your desired amount at the armhole and taper to the original shoulder at the neckline.
For a major adjustment pinch and pin out the excess fabric into a dart in the front armhole. Mark, fold out and tape the dart down on your pattern. Redraw (true-up) the armhole on the seam line. You may want to cut the seam allowance off, before folding out the dart and truing up the seam line (just add it back at before or while you cut out your fabric)
To adjust the sleeve pattern
For the minor adjustment, many sleeves will not need altering instead the excess fabric in the sleeve can be eased into the armhole. However, if there is too much sleeve or the fabric does not ease well cut a vertical line down the sleeve at the top about 3 to 4 inches.
Lap the edges the amount to be decreased and tape down.
Should the tissue pattern bulge when laid flat cut 1 ½” inches down into the sleeve beyond the notches (outside the eased area of the sleeve cap) to release the tissue paper.
Redraw the sleeve cap slightly lower (follow the curve of the cap).
Adjust the seam allowance/cutting line.
For the major adjustment measure the armhole* and the sleeve cap between the notches.
The sleeve cap (for a set in sleeve) must always have a little ease. Meaning the measurement between the notches on the sleeve will be larger than the measurement between the notches on the armhole.
If your measurements indicate the sleeve ease is less than 1 ½” you have the option to ease the excess into the armhole (it will depend on the style of the blouse).
If your measurements indicate the sleeve ease is more than 1 ½” cut the sleeve pattern horizontally across the cap from the front of the sleeve to, but not through, the back of the sleeve (since you reduced the armhole in the front only, you do not adjust the sleeve in the back).
Lap the edges of the sleeve front the amount removed from the bodice armhole and tape down the pattern.
True the seam line and add seam allowance.
* When measuring the armhole between the notches do not measure the shoulder seam allowance (it’s easy to do when your seam allowance is included and not marked on your pattern)
Make a muslin before cutting into your fashion fabric.
I hope this has helped. Thanks for your question.