Did you know: the full-bust adjustment is the most common pattern alteration. Some are full-busted from adolescence, and some get that gift along with motherhood. Regardless, the “FBA” is worth learning because you’re likely buying clothing that’s too large for you in the shoulders, so the front of you can be presentable.
Standard patterns are made for B-cup busts, so don’t try to make up the difference by sewing up a huge pattern. Instead, choose your pattern size by the measurement of your bust at the high-bust (under armpit). (This is one of the facts least-known to beginning sewers.) Thankfully, a full-bust adjustment is easy to make to the pattern tissue before you cut into your favorite fashion fabric. Here are a few pics of this adjustment for my sewing student Denise. I like the techniques in Palmer Pletsch’s book Fit for Real People. The technique we used is for those who have more than one inch to increase the center front. We needed two additional inches. How much do you need? Pin 1) the shoulders of the back and front tissue pieces together at the seam line and 2) the side seams at the seam line and try it on. Does the tissue come together in the front? If not, you need a full-bust adjustment. Measure how much is lacking. In our case, it was two inches, so we split the front bodice pattern in two places (we also had to cut elsewhere to allow the two main cuts to fall naturally). Note that we didn’t cut all the way through the pattern to the armpit. Instead we made a hinge by snipping nearly to the stitching line.
We then laid down a piece of foam board, then a large piece of pattern tissue paper, then the printed pattern. Using pins to anchor the hinges, we spread the right-most piece of tissue (as shown) one-half of the width needed (1″). We then spread to the left the other half (1″) resulting in two inches total. You can see a faint pen mark in the center of the white space in the photo above. To the far left, you can see that the bust dart became much wider. This is good: when sewn, darts help shape the garment. The armpit “hinge” also changed a bit, but the basic curve is preserved. Tape in all of the changes to the filler tissue below before removing the pins. The bottom of the pattern needs lengthening — all large-busted women dread the “tent” effect, created when a top is too short. Adding length to the pattern piece solves this problem (shown right).
Next time, we’ll try it on, pinned as before, and we’ll ensure it meets at center front. (Some people need the entire dart moved down if it does not end at the apex of the bust. In this case, we’ll just cut away the entire bust dart and move it down.)
Denise is looking forward to making her own blouses, in her best colors, with the neckline she likes, and avoiding the “tent” effect.