Today we are going to talk about bust adjustments for the Brynn pattern. I definitely  have some opinions on FBAs and SBAs on a knit garment, but first lets talk about what a full or small bust adjustment is.

What is a Bust Adjustment

Our patterns are drafted for a C-cup (0-18 size range) or a D-cup (14-32 size range). These are sewing cup sizes and not ready-to-wear cup sizes. This is very important. A sewing cup size refers to the difference between your upper bust and full bust and not your bra size. To figure out your sewing cup size, subtract your high bust from your full bust, and use the difference to compare to the following chart.

• 1″ = A cup.
• 2″ = B cup.
• 3″ = C cup.
• 4″ = D cup.
• 5″ = DD cup.
• 6″ = DDD cup

If your bust difference is more than the cup your size range is drafted for, you may want to do a Full Bust Adjustment. So for instance, if my upper bust is 29" and my full bust is 33", that is a difference of 4" or a sewing D cup. Since the 0-18 size range is drafted for a 3" difference, I would choose the size that corresponds with my upper bust measurement of 29" which is a size 0, and then do a 1" (0.5" each side) full bust adjustment to the size 0 bodice to get me a full bust of 33".

Conversely, if your bust difference is less than the cup your size range is drafted for you may want to do a Small Bust Adjustment. So for instance, if my upper bust is 29" and my full bust is 31", that is a difference of 2" or a sewing B cup. Since the 0-18 size range is drafted for a 3" difference, I would choose the size that corresponds with my upper bust measurement of 29" which is a size 0, and then do a 1" (0.5" each side) small bust adjustment to the size 0 bodice to get me a full bust of 31".

Undergarments Matter

One  thing I want to point out is that undergarments (or the lack thereof) matter. With our models we found a complete cup size difference depending on which bra they wore. Make sure you are wearing the bra you intend to wear with the Brynn when taking measurements and making fit decisions. It makes a huge difference.

IS DOING A BUST ADJUSTMENT ON A KNIT GARMENT OVERFITTING?

The only real answer to this is sometimes. The Brynn pattern recommends fabrics with 60% or more stretch. This means that most fabrics can accommodate extra width while retaining the fit of the pattern. I think if you are within an inch or so of  the measurement chart I wouldn't personally do an FBA or SBA on my first version of the Brynn. This is definitely what we saw during testing. I would sew it up as is and then only make adjustments if necessary on future versions of the pattern. Also, if you want to do a bust adjustment, but don't want to do the complicated version, you can do my cheater version which I will show first.

CHEATER SBA

A small bust adjustment is essentially subtracting a bit of width and length from the front portion of the pattern while leaving the rest of the pattern alone. Since the Brynn has no darts, you can pretty easily do just that without doing a traditional FBA. The only downside is that it does take a bit of width from the V neckline. This might be a problem if you have lots of inches to subtract, but otherwise I think it actually works well. So for instance, for the following example, the high bust is 32" and the full bust is 34" which is a 2" difference. Since the pattern is drafted for a 3" difference, I am going to cut out the size 6 and take a 1" SBA out of the front. Since the pattern is for half of my body, I will subtract 1/2" width from the front of the Brynn. 

Here are a couple photos of the cheater SBA. I subtracted 1/8" at the side seam  bust area, 3/8" at the middle of the neckline, and 1/8" length at the center front (making it more straight). You will also want to subtract a bit from the neckband where you took the length out on the front v neck. Also be sure to smooth out the new neckline.

CHEATER FBA

A full bust adjustment is essentially adding a bit of width and length to the front portion of the pattern while leaving the rest of the pattern alone. Since the Brynn has no darts, you can pretty easily do just that without doing a traditional FBA. The  only downside is that it does add a bit more width to the V neckline. This might be a problem if you have lots of inches to add, but otherwise I think it actually works well. So for instance, for the following example, the high bust is 32" and the full bust is 36" which is a 4" difference. Since the pattern is drafted for a 3" difference, I am going to cut out the size 6 and add a 1"  FBA to the front. Since pattern is for half of my body, I will add 1/2" width to the front of the Brynn. 

Here is a photo of the finished cheater FBA. I added 1/8" at the side seam  bust area, 3/8" at the middle of the neckline, and 1/8" length at the center front. You will also want to add a bit to neckband where you made the length longer on the front v neck. Also be sure to smooth out the new neckline.

TRADITIONAL SBA

If you have decided to go forward with a traditional small bust adjustment, you can follow the following steps, plugging in your own measurements instead.

For this tutorial I am using the following measurements:

Upper bust : 32" / Full Bust : 34" (Difference of 2" or a sewing B cup)

Since the 0-18 size range is drafted for a 3" difference, I chose the size that corresponds with my upper bust measurement of 32" which is a size 6, and then am going to do a 1" (0.5" each side) small bust adjustment to the size 6 bodice to get me a full bust of 34".

Start with your Front Pattern Piece (I am using the front for View A, but this process is the same for all views).

Start by holding up your pattern piece to your body and marking your bust point. Being a knit garment with no dart, it doesn't need to be exact. This is a very individual thing and circumstances such as breastfeeding, age and undergarments all play a role.

Make the following lines (marked in blue) :

A - Angled line from bust point to approximate 1/3 of armhole.

B - Line from side seam to bust point. Angled line from bust point to approximate middle of underarm.

C - Vertical line from bust point to bottom of bodice, parallel to grainline.

D - Horizontal line, perpendicular to grainline. I use the lengthen / shorten line for this.

Next, mark your armhole seam allowance (3/8") along the top of line A. Make a cut from the bottom of line C to the bust point, and continue cutting up thru line A until you reach the seam allowance. Cut the rest of line A on the other side of the seam allowance leaving a small hinge.

Make another cut along line B, ending right before the bust point to leave a small hinge.

Create line E. This line is parallel to line C and the same length. The distance between line A and E is the full amount you are trying to decrease from your full bust (for me this is 1") divided by 2 since this is one side of your bust. So I am marking line E 1/2" in towards center front from line C.

Using the hinges you made, swing the left cut edge of line C over to line E. This will raise the bust point and shorten the bodice. Tape.

You will notice that the center front is a bit too long for the left side of the bodice. Cut line D (you may need to untape it a bit first). Move the bottom center front section straight up so that the bottom of the left side is in line with the right side.

If, like me, you feel like the side seam is getting really short, you can come up half way and then lengthen the side seam a bit to match.

Almost done. We need to do is adjust the side seam and armhole. They got a bit wacky so they smoothed out. 

The last thing to do is subtract the same length adjustment to the Neckband and Neckband Interfacing pieces. You also need to compare the side seam of the Front and Back and adjust so they match.

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TRADITIONAL FBA

If you have decided to go forward with a traditional full bust adjustment, you can follow the following steps, plugging in your own measurements instead.

For this tutorial I am using the following measurements:

Upper bust : 32" / Full Bust : 36" (Difference of 4" or a sewing D cup)

Since the 0-18 size range is drafted for a 3" difference, I chose the size that corresponds with my upper bust measurement of 32" which is a size 6, and then am going to do a 1" (0.5" each side) full bust adjustment to the size 6 bodice to get me a full bust of 36".

Start with your Front Pattern Piece (I am using the front for View A, but this process is the same for all views).

Start by holding up your pattern piece to your body and marking your bust point. Being a knit garment with no dart, it doesn't need to be exact. This is a very individual thing and circumstances such as breastfeeding, age and undergarments all play a role.

Make the following lines (marked in blue) :

A - Angled line from bust point to approximate 1/3 of armhole.

B - Line from side seam to bust point. Angled line from bust point to approximate middle of underarm.

C - Vertical line from bust point to bottom of bodice, parallel to grainline.

D - Horizontal line, perpendicular to grainline. I use the lengthen / shorten line for this.

Next, mark your armhole seam allowance (3/8") along the top of line A. Make a cut from the bottom of line C to the bust point, and continue cutting up thru line A until you reach the seam allowance. Cut the rest of line A on the other side of the seam allowance leaving a small hinge.

Make another cut along line B, ending right before the bust point to leave a small hinge.

Draw two line on a piece of paper the full amount you are trying to increase your full bust (for me this is 1") divided by 2 since this is one side of your bust. So I am drawing them 1/2" apart, perpendicular to one another.

Tape the bodice to the paper with line C on either sides of the lines. This will open lines B and A.

The left side of the front got quite a bit longer. To fix this, cut line D on the center front side and bring it down so the hems match.

Almost done. We need to do is adjust the side seam and armhole. They got a bit wacky so smooth them out as needed. Also, the side seam no longer matches the back side seam. You  will need to adjust one to match the other, or go somewhere in between.

The last thing to do is add the same length adjustment to the Neckband and Neckband Interfacing pieces.