What is Sway Back?
It is an inward body curve at the lower back waist above the posterior.
If your pattern pools and wrinkles across back below the waistline.
|Sway Back Adjustment, The Vogue Sewing Book, Copyright 1970|
MELODY NOTE: Alterations and pattern adjustments work like this: head to toe or top to bottom; basically bodice to skirt if you will. So... the sway back adjustment in a dress back block is a skirt (bottom) adjustment. Therefor all bodice (upper) adjustments must be made first. Why? The way a garment hangs and/or is adjusted across the shoulders, back or bust will in turn affect the pooling and wrinkles located at the lower center back.
|Dress blocks do not have waistline seams, the bodice and skirt back are one piece. |
The sway back adjustment happens where the waistline falls on the block.
For this pattern adjustment I am demonstrating on the Simplicity 3833 shift dress back pattern piece but the adjustment method will apply to any dress back block. A dress block has no waistline seam, the bodice and skirt back are one piece.
How to perform the adjustmentFind Sway Back Measurement:
- Correct Muslin Garment:
- Pin out wrinkles that are pooling at center back. Staring at the center back pinch excess and pin tapering to side seams. (Pinning your own back side is next to impossible, find a friend to assist.)
- At the center back measure from the pin to the folded edge of the pinch.
- The pinched fabric is a fold (2 plys) of excess fabric. You must double your measurement to get your sway back adjustment measurement.
- In my example I measured 1/4"(0.64 cm) * 2 = 1/2" (1.27 cm)
- My sway back adjustment measurement is 1/2"(1.27 cm)
Adjust Dress Back Block Pattern
1. Draw a line to extend waistline across dress back, from the center back through side seam.
2. Mark Pattern
- At the center back seam measure down from the drawn waistline line the distance of your sway back measurement and draw a little line.
- At the side seam mark a pivot point on the drawn waistline line
3. Cut Pattern Adjustment Line
- Cut at the drawn waistline line through the center back seam to the pivot point.
4. Slide the cut waistline down at the center back to the little line, keeping the pivot hinge intact and allowed to open. Tape to secure.
5. Adjust Center Back Hemline
Adjusting the skirt at the waistline affects the hemline (top to bottom... see MELODY NOTE above). Wedging out the excess fabric at the center back waistline in the sway back adjustment will also cause the hemline to wedge up. Therefor the next step is to correct this swoop at the hem by adding the wedge back to the center back of the hemline.
At the center back seam measure down from the hemline the distance of your sway back measurement and draw a little line.
Use a curve to connect new lowered center back drawn hemline line to the hemline at the side seam on the back piece.
Check the Darts
If your bodice back block has fish-eye darts - check to make sure that the darts are still parallel to the center back seam. If the sway back adjustment has caused the skirt ends of the dart to shift you will need to realign that end of the dart.