Today we’re talking FBAs – the adjustment that everyone loves to hate 
Actually it’s pretty easy, and once you discover it, you’ll never go back. It’s always a good idea to choose a dress/top/jacket pattern using your high bust measurement (line 1) not your full bust measurement (line 2) if you’re above a B cup. This way, the top will fit at the shoulders, which is great because shoulders are hard to adjust without changing *everything* else. Of course, your boobs will be too small, so that’s why there’s such thing as an FBA
First, make a toile of the bodice only and transfer the opening from the back to the front (ie: sew the back seam and give the centre front a seam and don’t cut it on the fold). Now, try it on and don’t pin it shut quite yet. Measure two things. 1. The distance from your centre front to the actual bodice centre front seam – this is how much you’re going to need to add in the FBA. 2. Mark your bust point on the toile.
Now, trace your pattern onto some butchers paper or the like. I traced mine onto printer paper so what I’m doing is ultra clear for you to see what I’m doing. I always trace my pattern pieces when making alterations. This is because if you mess up so badly that the pattern piece is unrecognisable (I’ve done this), you haven’t defaced your original pattern and it’s all good. Just start again (after a glass of wine, and a small bitch session to someone who cares to listen).
My traced pattern piece looks like this.
You’ll notice two lines named HBL. These are horizontal balance lines – when you make alterations it’s important to keep these lines parallel with the floor in the same way that the grain lines is perpendicular to the floor. I use the lengthen/shorten lines as convenient HBLs. Also, I’ve recorded the location of my bust point and start of the arm hole.
This piece is the centre front piece, but it does join a princess seam side front piece. I’m lucky here because I’ve got a dart to play with in my FBA. If you don’t have a dart, you’re doing an FBA for a princess seam (not covered here). This is the same FBA alteration you’d do if you didn’t have a side front piece, but the centre front joined the centre back at the side seam directly.
Now, draw three lines as shown in red.
The first one is from the BP (bust point) to a location approximately 1/3 of the way up the arm hole. The second is from the BP to the centre of your dart and the third is straight down from the BP to the bottom – ENSURING it is parallel to the centre front straight grain line.
Now, make a cut as shown, leaving a small ‘hinge’ of paper where your cut line meets the arm hole.
Make a second cut as shown leaving a small hinge again at the bust point.
Now cut the centre front portion of the pattern piece at the HBL as shown. If you don’t have an HBL here, just cut it approximately, it’s just to lengthen the piece evenly.
Now you’re probably seeing where I’m going with this, so put some more paper under your pattern and spread your pattern so that your parallel lines are the width apart that you determined when you tried on your toile (for me, it’s 1.5cm) and make sure this distance is consistent all the way down. Tape your pattern down.
I like my darts to be pointing towards my bust point, so I drew a line from my bust point to the centre of the dart made by my FBA
I then drew a new dart (in red) from the original dart starting points to a point 2.5 cm from my bust point. I think this distance depends a lot on how fitted you want the bust to be and how big your boobs are.
And there you are – your new pattern. Notice that the side seam is not affected, so there is no alteration needed to the side front princess seam. Notice your pattern has gotten longer! Make sure to made adjustments to other pattern pieces as well to accommodate for this.
Do you routinely do FBAs?
Relax and Enjoy,
Kat
Sadly I’m not in the market for a FBA, but I hear there’s a SBA (small bust adjustment) that is essentially the opposite of the FBA, although I have yet to try it. It’s exciting to think about though, since I’ve passed on buying/making too many dresses because the bust was too big for me!
I felt like I had found a secret code once I figured out how to add FBA’s to patterns! Love the technique! As you point out, shoulders fit sooooo much better when you pick a size based in upper bust and adding an FBA.
I know! Fitting actually is *easier* when you know an FBA.
This is very timely Kat in view of my recent experience with Colette Peony where I destroyed the original pattern trying to adjust for my full bust and narrow shoulders. Thanks.
Hey, no worries! Enjoy
Am petrified of doing an FBA despite having a DVD on it and lots of online resources in addition to book sections. But am getting there. Yet to make a top.
Hey Sassy T! I’d say just go for it! Get a top pattern and make it up in calico and go nuts! If you make your top in cheap fabric first you can play with no guilt! I’m rooting for you!!! Do it!!
I do the sba but it’s helpful to see the fba because the sba is pretty much in reverse of the fba. But another thing that really helped me was getting the right measurement. I was using my bra size which was huge and then do the sba. Now, I use the upper chest or bust measurement and I’ve gone down considerably in size which make the bust adjustment much easier and in some cases not needed at all. I have no idea what women with small upper measurements and C cups do. Weep quietly in the corner? If you think about it sewing can really be a pain in the A$$. But, I still love it.