Full Bust Adjustment

Of all the pattern alterations, the Full Bust Adjustment (FBA) is the most important one with which to be proficient.  The name is a bit misleading.  You may assume that only women with large busts need a FBA.  That is not necessarily true.  If you choose your pattern size correctly (see Buy the Right Pattern Size)  you will find when you try on your pattern, that the center front will not meet.  That is because when you choose the right size pattern, you measure the High Bust and fit the pattern to your neck and upper chest.  This will be a smaller size than the bust size.  Why do we do that?  Because we want the pattern to fit closely across the upper part of the chest, with no extra fabric bunching in this area.  It is easy to do a full bust adjustment.

The full bust adjustment does one very important thing.  It adds fabric across the bust area, where you need it.  If you buy a pattern size that matches your bust measurement, you get too much fabric all the way from your neck and upper chest down, giving very unattractive fullness.  If you buy the correct pattern size, but add the extra fabric at the side seam, you get extra fabric under your arms, but still get pulling and gaping at the chest.  Furthermore, you often get stretch lines at the armholes.  So the simple FBA is the answer to altering a pattern so that the extra fabric is over the bust.

How To Determine if You Need a Full Bust Adjustment?

Pin the front dart in the pattern.  Pin the shoulders and side seams together.  Try on the pattern.  If you need a FBA adjustment, one of two things will be apparent.  The first, and most obvious, is that the center front of the pattern does not meet your center front

If this is the case, measure the distance from the center front of your pattern, to your own center front.  This will be the amount of FBA you need to make.

The second scenario, would be that the center front meets, but there is a wrinkle by the front armhole that points to the bust.  The wrinkle is showing that there is a pulling of the fabric, because not enough is covering the bust.  In this case, you should add about a 1" FBA to your pattern.

How to Alter a Pattern With a Full Bust Adjustment.

There are three simple steps.  Use the above method to determine how many inches to add with your full bust adjustment.  Now we are ready to alter the pattern.

Step Number One:

Draw Line 1, from the bust point straight down to the bottom of the pattern, and from the bust point to a spot about 2/3 the way down the armhole.  Next, cut the pattern from the bottom , to the bust point and to, but not through, the armhole.  Pivot this piece out the measurement that you need, at the bustpoint.

Step Number Two:

Draw Line 2 from the Bust Point through the middle of the dart.  Cut through the dart, to, but not through the point.  Rotate this piece so that you open the dart and the lines from the bust point are parallel.

Step Number Three

You notice that the left side of the pattern is shorter than the right side of the pattern.  Draw Line 3 near the bottom 1/3 of the short leg.  Cut through Line 3, and line up the bottom edges.  Fill all of the open spaces in with Palmer and Pletsch Perfect Pattern Paper.  Redraw the dart.