Completing an FBA on our Esteem Dress isn't always the most straight forward adjustment considering non- traditional bodice type. There are a few differences, mainly the pattern pieces, but generally, we're still using the same points to expand the bust line out and create some extra space.
So, let just say it outright so Google throws this tutorial at you when you're looking for a Full Bust Adjustment of this sort.
What we will be completing is a Full Bust Adjustment on a princess seam.
Let's get started.
First, let's mark the bust point on pattern piece A. For this design the bust point is approximately 5cm (2") below the collar line, on the curve of the bodice separation.
Mark the bust point on pattern piece B at the point where the two pieces match up. You can put that marking 1 cm (3/8") from the edge to compensate for the seam allowance.
Now, because I've incorporated the shoulder strap into pattern piece B, we need to free things up a little bit.
Mark a point at the lowest spot in the underarm curve. From there, draw a line perpendicular to the base edge of the pattern piece. Then trim away the strap section and set aside.
Next, draw a line 1 cm (3/8") from the bust point along the edge and following the path of the curve down to the straight, base edge. Then, draw a line from the bust point to the shoulder strap edge, parallel to the base line. The next line will be from the bust point to a point half way between the leading edge of the underarm curve and the end.
Cut it up as shown below. Keep just a little nibble of paper connected at the joint to help pivot.
BUST ADJUSTMENT. HOW MUCH?
For our particular design gauging the finished bust measurement wasn't really doable. We've got an open back...Half the bodice is not even there. If you are reading through this tutorial it's because you've completed a muslin draft of at least the bodice and have realized you would like some extra room in the bust. So, let's go ahead and do that!
DETERMINE YOUR SIZE
When deciding what size to work in the Esteem Dress, reference the high bust measurement rather than the bust measurement to determine your size. This will ensure the width across the chest and waist fit better. The high bust measurement is the circumference measurement taken under the arm pit and above the bust apex.
Compare your high bust measurement against your bust measurement. Generally, a 5 cm (2") difference would mean a B cup, 7.5 cm (3") difference a C cup, 10 cm (4") a D cup, and a 13 cm (5") a DD cup.
Measure your full bust measurement and compare that to the high bust measurement of the bodice size you are working.
For example, our high bust measurement is 83 cm (32.5") but our full bust measurement is 88 cm (34.5"). Our HB puts us at a size 2-4 and our FB puts us at a size 6-8. The difference in the measurement is 5 cm (2"). We need to divide that number by 2 because we will be working on a pattern piece will be placed on the fold and doubled. 5 cm (2") / 2 = 2.5 cm (1") This will be our adjustment.
Place paper behind the pattern piece. Using your adjustment length, determine where your pattern B curve should align.
Now, I do not need any high waist adjustment, so I've trimmed the curve and have eased the pattern B curve back towards the original base edge point.
If a high waist adjustment would be appropriate for you just take that curve all the way to a point level with the base edge of the pattern piece.
Secure the pattern piece in place with tape.
Trim away the excess paper and join pattern piece B back together. You might notice a slight height difference and can fill that space by securing a piece of paper behind the pattern piece and trimming away the excess.
We need to determine the length adjustment on pattern piece A now. Match the pattern pieces at the underarm edge and pivot the pieces together through the edge.
When you get to the base you'll see the difference in length. I've got about an inch of length that I need to add to pattern piece A.
Cut through pattern piece A about 5 cm (2") above the base edge. Secure a piece of paper behind the pattern piece, separate and apply the length to the pattern piece. Secure in place with tape and trim away the excess paper.
DONE.... I highly encourage you to create another muslin before cutting into your quality fabric to make sure your fit will be right on!