Full Bust Adjustment Part 1 – Dartless Bodice

When making garments for someone with a larger bust – whether yourself or someone else – you may want to consider a full bust adjustment (FBA) to achieve a perfect fit. FBA is recommended when there is a difference of 7.5cm (approximately 3”) or more between your upper bust and your full bust measurement. The FBA is intended to increase room around the bust area in your garment, without altering the fit at the shoulder or waistline.

There are many resources in print and online to learn how to do FBAs on dartless bodices, but for the Cuff Top, the adjustment process is a little different because of the grown-on sleeve. Since this pattern does not have a defined armscye (armhole), this tutorial will show you how to take a couple of extra steps to do a FBA and ensure a better fit. 

Tip: When making major modifications to a pattern, I always recommend starting with a draft pattern made from muslin or inexpensive fabric to check the fit and make additional alterations if needed. Thrift stores are excellent places to find inexpensive fabric – you can often find donated yardage of fabric, and bedsheets and duvet covers also make great options for tester garments before you cut into your expensive fabric!

You’ll need:

• Measuring tape
• Paper pattern
• Extra paper
• Tape
• Pencil
• Ruler (a clear grid ruler is a great choice!)

Calculate FBA Measurements

Step 1: First, take your upper bust measurement, by measuring around your chest and under your arms, as pictured below. This measurement will help you determine which pattern size to begin with. It is recommended to choose the pattern size where the indicated full bust measurement (typically just referred to as “bust”) most closely aligns with your upper bust measurement.

Note: The Cuff Top offers a generous fit, so when determining which size to start with, I recommend looking at the finished garment measurements and choosing the option that is closest to your body measurement including (at least) an extra 5cm (2″). For example, if your upper bust measurement is 117cm, then it may align best with the size L, which has a finished measurement of 122cm. This should account for enough ease for a comfortable fit. You may wish to include more ease at your preference.

Step 2: Next, take your full bust measurement, which is the distance around the fullest part of your bust (note that it may not be exactly at the nipple line). Be sure that your measuring tape is horizontal (perpendicular to the floor). Use a mirror to help align, and you may even want to recruit a friend to help with these measurements to ensure they’re accurate!

Step 3: To determine the amount that you will add to the pattern for your FBA, you’ll need to do a little math. Take your upper bust measurement and deduct it from your full bust measurement. For example, if your upper bust measures 110cm (43.25”) and your bust measures 120cm (47.25”), the difference between the two is 10cm (4”). This means you’ll want to add a total of 10cm (4”) to your pattern at the bust. Since the pattern piece is only half the bodice, we divide 10cm in half so the adjustment is evenly distributed on each side of the pattern; this means we will add a total of 5cm (2”) to the front bodice pattern.

Note: For the Cuff Top pattern in size XL and up, you may want to reduce this number by another 2.5cm (1”) because the larger size range already has some additional bust room included. For example, if you were using the same measurements above, you would add a total of 7.5cm (3”), which is divided in half to become 3.75cm (1.5”) added to the front bodice pattern.

Making the FBA on the Pattern:

Once you’ve chosen the best size pattern for your starting point (see step 1), you will make some modifications to the pattern. I recommend tracing a new copy of the pattern in case you need to reference the original.

Step 4: First, hold the pattern up to your body and align the centre front and shoulder seams. Mark your bust point (BP) on the pattern (the fullest part of your bust – remember this may not be in line with the nipple).

Step 5: Next, we need to temporarily remove the sleeve to ensure that fullness is distributed where we want it. Draw the shape of an armhole on the pattern, connecting from approximately 6.25cm (2.5”) above the side notch to approximately 2.5cm (1”). This part does not need to be precise, so do not worry about the exact angle of the curve. Alternatively, you could draw a straight line connecting the two points.

Add a notch approximately ⅓ of the way up the armhole from the underarm. Cut the sleeve off along this line and set it aside.

Step 6: Draw a vertical line down from the BP to the hem. Draw a straight line connecting the BP to the armhole notch that you drew. Note: For patterns without sleeves, begin at this step.

Step 7: The next line will allow us to open the pattern to add fullness at the bust, and will also be the location of the new dart (though you do not need to add a dart – see options below). Normally this line is drawn at 90 degrees to the vertical line, but because of the shape of this pattern, we are going to angle it downward and connect it to the side notch.

Step 8: Cut up along the vertical line to the BP and out along the upper angled line toward the armhole but do not cut through – leave the pivot point connected.

Step 9: Cut inward toward the BP along the remaining line but do not cut through at BP, leave the pivot point connected.

Step 10: On a separate piece of paper, draw two vertical lines measuring the length of the bodice from neck to hem. The distance between the lines should be the amount of added fullness you would like to add to your pattern. In this example, I am adding 5cm (2”) fullness (a total of 10cm (4”) overall across the full front bodice) so my vertical lines are 5cm (2”) apart.

Tape your bodice pattern down to the paper, aligning the vertical cut line on the pattern with the right-most vertical line on the new paper.

Step 11: Gently slide the side pattern piece down until the pattern cut line is aligned with the left-most vertical line on the new paper.

Step 12: Draw a horizontal line approximately 7.5cm (3”) up from the hem, as pictured. Cut along the line and slide it down to match the position of the hem on the other side of the pattern.

Finishing the FBA – Dart or Dartless Options

For a fuller bust, I would suggest including a dart at the side seam to help with shaping and the fit of the garment. However, depending on your preference you can choose to add a dart or not. To add a dart, see below. If you opt for no dart – skip to Step 19. Unsure which option to choose? Scroll to the bottom of this post to see sample garments showing a FBA with and without darts.

Adding a Dart

Step 13: Tape the pattern securely to the backing paper. Add more backing paper if needed so that the side openings on the original pattern can be taped securely, as pictured.

Step 14: Draw a line from BP to the centre of the opening on the side seam. This line is the centre of your new dart. Measure 5cm (2”) away from BP and mark on the line. This mark is the end of your dart. The dart should not end right at BP, to ensure a smooth fit.

Draw the new dart legs, connecting from the dart end to the openings along the side seam.

Step 15: To determine the accurate shape of the dart at the side seam, some folding is needed. First, fold the pattern along the line indicated below, passing through the dart end, to make it easier to manipulate the dart.

Step 16: Next, fold along the lower dart leg, and pull that dart leg up to match the upper dart leg.

Step 17: True the side seam with a ruler, reducing the hem the same distance as was added in the FBA. In this sample I added 5cm (2″), so reduce that amount at the hem, blending smooth at the underarm/dart opening area.

You can use a tracing wheel to mark the line, or you can simply tape the pattern together at the dart, and cut along the side seam (then remove the tape). I have angled the side seam to be perpendicular for approximately 6cm (2.5″) from the hem, to help keep a straight hem and side seam connection on the final garment.

Step 18: Add the sleeve back to the pattern, matching the underarm point first, and connecting to the shoulder. True the shoulder seam from neckline to sleeve hem by drawing a new straight line from neckline point to hem, along the sewing line. Add your seam allowance of 1cm (3/8”) to this line. Cut away the excess.

I’ve gently angled my shoulder seam to meet the cuff hem at a perpendicular angle to help keep the hem straight, which will make the installation of the elastic a little easier. You can adjust this to your preference.

Opting for No Dart – Two Options

If you prefer no dart, the process to finish the pattern is a little different. For the Cuff Top, if you do a FBA and choose not to add a dart, please note that the fit will be different in the bust and the hem does not lay as straight as it will if you include a dart. There are two options: you can adjust the pattern to eliminate the dart (which incorporates extra volume at the waist by default), or you can explore tapering the side seam to keep the waist dimensions the same as the original pattern.

No Dart – Option 1

Step 19: First, slide the pattern back up so it closes the opening at the side seam notch.

Step 20: Pivot at the side seam point so the inner piece of the pattern overlaps itself, straightening the pattern at inner cut line so it is close to parallel to the vertical line on the backing paper (it will not meet that line). Tape the pattern securely to backing paper.

Step 21: Add the sleeve back to the pattern, matching the underarm point first, and connecting to the shoulder. True the shoulder seam from neckline to sleeve hem by drawing a new straight line from neckline point to hem, along the sewing line. Add your seam allowance of 1cm (3/8”) to this line. Cut away the excess.

I’ve gently angled my shoulder seam to meet the cuff hem at a perpendicular angle to help keep the hem straight, which will make the installation of the elastic a little easier. You can adjust this to your preference.

Step 22: Blend the new side seam from the underarm where it connects to the sleeve. Draw the new hemline, creating a perpendicular line at side seam to allow a smooth seam connecting back bodice to front bodice.

No Dart – Option 2

Step 23: This process has added extra volume at the waist. To remove this volume you can taper in at the side seam by the amount that was added, however, depending on the design this may cause a poor fit. The process is pictured in the two images below, but I would recommend testing this with some muslin or inexpensive fabric first, as it may not always produce the results (and the fit) you desire.

For the Cuff Top, in my test sample it caused extra drag lines at the bust and the back, and an uneven hem. I would recommend the darted option for FBA in this pattern for best fit. Photos of each of these FBA pattern modifications are below.

FBA – Test Garments

From left to right: FBA with bust dart, FBA without dart (No Dart Option 1), FBA without dart and with waist width adjusted to original size (No Dart Option 2). You can see that the first option with the dart has the least tension around the bust area. The FBA without dart (centre) has extra volume at the waist at the front, but eliminating that extra volume (without including a dart) may cause poor fit.

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