This correction is very similar to the “shoulders too wide” adjustment, but instead of closing the slash, you are opening it.

The issue usually comes from the Low Point Shoulder (LPS) being too high at the armhole area, often creating draglines from a tight across-front area.

This method is ideal when you want to increase shoulder width while keeping the armhole unchanged.

Step-by-Step Slash and Spread Adjustment

1. Slash open the armhole at the LPS. Tape and pin the amount you want to increase in the across-shoulder area at the armhole.
2. Measure the amount you’ve taped and note it down.
3. On your bodice pattern, draw a straight line from about 1/3 of the way up the shoulder seam to the curve of the armhole.
4. Draw a second line from the LPS to the midway area of the first line.
5. Cut along those lines, ending at zero at the armhole join and zero at the LPS.
6. Slash the main line and open it the same amount you’ve taped.
7. The second line will join the shoulder seam, and you will redraw the shoulder seam straight again.
8. Apply the same correction to the back bodice piece.

This information and more can be found in The Fitting Book. Order your book today through the link below.