FBA: Princess Seam Bodice

How to complete a full bust adjustment (FBA) on a bodice with princess seams

Today we are continuing our bust adjustment series, and talking about princess seams. There are multiple ways to complete a princess seam FBA, and this method is just one of them. All Boo and Lu pattern tutorials include detailed instructions for personal body adjustments. Follow the instructions given for a bust adjustment for that particular pattern. Today’s post will give you a good start on making bust adjustments on a bodice with princess seams (such as the Orchid dress or Onyx blazer).

Let’s begin!

If the pattern you are adjusting does not include apex markings, add them first.

Adjusting the side bodice piece

Draw the seam allowance of the side front bodice piece. You do not need to draw in the seam allowance at the side seam.

Draw three lines: Line A goes horizontally across the piece to the bust apex (the notch), line B goes from the bust apex down to the seam allowance at the bottom, and line C goes from the apex up to the seam allowance at the top of the armscye.

Cut up line B and C, stopping at the seam allowance and make a little hinge by cutting into the seam allowance on the other side. Swing the right section up.

Cut line A from the side seam leaving a small hinge at the end. Swing the bottom piece down and adjust the pieces so that the vertical opening has parallel sides and the opening is the width you need to add for your FBA.

Tip:

See Bust Adjustments 101 to learn how to measure your adjustment!

The left side of the bodice now needs to be adjusted so that the bottom hem matches the length of the right side. Cut across the lefthand side piece and slide the bottom piece down to align at the bottom. You will need to measure the gap that opened up – Gap A. Write this measurement down.

Trace the pattern piece, including marking where gap A begins, and draw the dart that has been created. Make sure to include the apex notch.

On your new piece, draw a line that goes across the bottom leg of the dart to the edge of the piece. Cut through that line from the side seam, all the way to the end of the dart. Snip into the line from the seam allowance side, creating a hinge. Swing the bottom piece up to close the dart and tape closed. When you do this a small gap will open on the princess seam by the notch, but it will be filled in during the next step.

Re-trace the pattern piece. Make sure to mark gap A and the notch.

Adjusting the center piece

Next, you will need to adjust the center piece to match the side piece.

To adjust the center of the bodice, measure the distance from the bottom of the side piece to gap A. Measure that same distance from the bottom of the center bodice piece and draw horizontal lines across at the height of gap A. Also draw a line just below the notch.

Cut across both horizontal lines and spread the pieces apart: First spread the bottom piece down the amount you noted for Gap A. Then, measure the total distance from the bottom of the side piece to the notch of the side piece, and spread the other center bodice piece the amount needed to match the distance. When you are finished, double check that the distance from the bottom of the bodice to the notch matches on both pieces.

Trace the new piece.

Adjusting the side seam

Finally, the waist needs to be adjusted. When doing an FBA, the waist seam becomes wider, so it needs to be brought back in to its original width.

Take the original side front pattern piece and place it over the new side front piece lining it up at the center front where the waist hits. (1) Draw a new side seam, beginning at the new piece’s armscye, and ending where the original waistline ends. (2, 3) Make sure the seam does not start to taper in to the original waist until you are below where the dart was closed. Cut out the final piece. (4)

When adjusting the side seam, the length may have changed. Be sure to adjust the back bodice side seam accordingly if needed.