SSS Day 9 (or How I Do an FBA)

Well, I cut this Simplicity top out last night, sewed it up this morning and will wear it all day.   I need long-sleeved tops, and I thought this would be the perfect top to sew up so I could continue with the SSS project.

I cut the size using my upper chest measurement as a guide and did an FBA since I really wanted to have the shoulder, armhole and chest fit snugly enough not to worry about gaping while wearing it.


FBA slash & spread method


I always use Vogue Sewing Book’s method of doing a full-bust adjustment.   It’s the most fool-proof and accurate way of doing a full-bust adjustment I’ve ever done, and I use it on everything, including patterns that apparently can’t be altered above the waist.

This bust adjustment is easy to do:

  1. mark the bust point
  2. draw a vertical line exactly parallel to the centre front line from the bust point through the waist or hemline
  3. draw a line from the armscye (I usually use the notches on the armhole as a guide) to the bust point
  4. draw a third line from the bust point to the side seam at the point where you’d like your dart to be.  Sometimes I do two darts, depending on how fitted I want the bodice to be.
  5. put a small piece of Scotch tape over the bust  point and at the armscye notch (or at the point where the underarm line meets the armhole seam
  6. slash up the vertical line from the hemline TO BUT NOT THROUGH  the bust point
  7. slash along your line from the side seam TO BUT NOT THROUGH the bust point
  8. slash from the bust point TO BUT NOT THROUGH the seam allowance of the armscye

Now you’re ready to lay out the pattern.


FBA detail


Lay out the pattern on the fabric ensure the grain lines are accurate.
Pin the front edge, neckline and shoulder to the fabric, leaving the side, armscye and hemlines free.
Now here’s where you spread as much as you need:

  • C cup spread 1/2 inch
  • D cup spread 3/4 inch
  • DD or E cup spread 1 inch
  • etc, etc, for larger cup sizes as required

Notice that the amount of spreading at the bust point is carried down through the vertical slash to the hemline.  You may need to adjust the waistline in on your garment.  This adjustment works as is for me because I cut one size larger for my waist and hips than I do for my bodice, and it eliminates the hip alteration due to the width added in the FBA.

Mark the dart(s) at the side seam.  You can see the pattern will give you a good idea of the depth and width of the dart.  You can add more than one dart, depending on how fitted you want the bodice to be.  Dart points should end within an 1″ radius of the bust point.

This is my favourite FBA technique as it’s virtually foolproof and respects the integrity of the arm and neckline design.  Have fun trying it out in your sewing adventures.

2 thoughts on “SSS Day 9 (or How I Do an FBA)

  1. You know, I wish I had a nickel for every time I have referred back to this post. Thanks for making a FBA so understandable Tia

    1. You are so welcome, Kerry! FBA’s are hard to wrap your head around from pattern to pattern, I find. I have a diagram pinned on my bulletin board for quick reference when I have a “huh?” moment staring at a pattern than needs an FBA!


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