Broad Back Adjustment for the Willow Top (Differences >2"/5cm)

August 21, 2026

This tutorial will guide you through a technique for doing a Broad Back Adjustment of greater than 2" (5cm) for the Willow Top. Use this adjustment if you find that more space is needed between the shoulder blades for fit and comfort. Signs of needing a broad back adjustment include a garment feeling tight across the upper back (which may produce horizontal wrinkles across the back) and restricted movement when reaching forward.

Materials

Gather some basic materials to adjust the pattern pieces:

Pattern pieces - Willow Top Centre Back, Side Back, and Shoulder Yoke
Scrap paper
Tape
Pen/pencil
Ruler

Measure

To determine the amount you will need to adjust the pattern piece, compare the 'shoulder width' measurement from the Finished Garment Measurement Chart in the pattern tutorial to your actual shoulder width measurement.

Measure across the top of your back from the crease where the top of your arm joins your back, from one side to the other. This is easiest if you get someone to help you measure.

Diagram illustrating how to take shoulder width measurement for sewing

The amount that needs to be added to the combined back pattern pieces (Centre Back and Side Back) will be half the difference between the two measurements. Note that the shoulder width measurement in the Finished Measurement Chart is taken with the elastic unstretched. The firmness of the elastic used will impact the stretchiness of the Centre Back panel. It may be necessary to make additional adjustments to the elastic lengths while sewing the top (the pattern tutorial explains how to do this).

Adjust Willow Top pattern pieces

The following pattern pieces will need to be adjusted to do a Broad Back Adjustment +2" (5cm) for the Willow Top: Centre Back, Side Back, and Shoulder Yoke.

1. Draw cut lines on the pattern pieces as shown in the illustration below (left, Shoulder Yoke; centre, Side Back; right, Centre Back).

2. Cut along the marked lines, leaving a small amount of paper intact on the side seam allowance of the Centre Back piece to use as a pivot point. The cut lines on the Side Back and Shoulder Yoke pieces should be cut through.

3. Place a piece of paper underneath the pattern pieces to secure them in place after the adjustment is made. We will divide the total adjustment amount between the Centre Back and Side Back pattern pieces.

4. The total adjustment amount will be divided across the pattern pieces as follows:

Add 2/3 of the adjustment amount to the Side Back by sliding the cutout piece horizontally along the cut line.
Add 1/3 of the adjustment amount to the Centre Back by pivoting the cutout piece out and away from the pattern piece.
Add 2/3 of the adjustment amount to the back edge of the Shoulder Yoke piece by sliding it out (the cut out piece should remain aligned with the edge with the double notches).