Bust adjustments for jumpsuits and pinafore patterns

Sewing patterns for jumpsuits, overalls, pinafores, and other apron-style designs often have a flat front bodice (the bib of the garment) that is drafted without any shaping. This page explains how to resolve fit issues for larger cup sizes by adding darts to the bib.

The instructions below can be used to adjust the bodice of these Studio Minapop sewing patterns:

• the Ellie pinafore
• the Birch top
• the Max jumpsuit (coming soon)

Instead of adding darts, you can also do a full bust adjustment (FBA).

 

Adding darts to the bodice 

To add darts to the bodice, we need to determine the placement and width of the dart.

1. Measure across your high bust and full bust. 

• Your full bust is the widest part of your bust.

• Your high bust is the area right above your bust, below your armpits.

2. Calculate the difference between these two measurements. For example, if your full bust has a circumference of 96 cm (37.8”) and your high bust measures 90 cm (35.5”), you have a difference of 6 cm (2.3"). This difference determines your cup size, and how wide your dart needs to be. Find your dart width in the table below:

In our example the difference was 6 cm (2.3"), so the corresponding cup size is C and the dart width is 3,5 cm (1 1/2”). These dart widths are a good first indication. You can alter the size of your dart depending on what fit you want (you can find further suggestions at the bottom of this page).

We will now determine the placement of the dart on the pattern, starting with one side of the bodice.

3. Take the front bodice piece and determine where the apex of your bust will sit. The apex is the fullest part of your bust (for most people this will be the nipple). Mark this point on the pattern piece. 

4. Take a separate piece of pattern paper and copy the front bodice piece, including the mark for the apex point and the center front (CF) notch. We will later need some extra room along the side seams to accommodate the dart, so don’t cut out this piece yet (or if you do, leave some extra paper along the edges).

5. Draw a line from the apex point to the armpit side seam of the bodice. This will become the center of the dart. You can choose at which angle to draw the dart. A good starting point is to make it perpendicular to the side seam. 

6. Measure 2,5cm (1”) away from the apex point, along the dart center, and mark this new point. This will become the point of the dart.

7. Along the side seam, measure half of your dart width up from the dart center, and half of your dart width down. So if your dart width is 6 cm, measure 3 cm up and 3 cm down. Mark both points. The width between the two points should now equal your dart width.

8. Draw two lines, starting from the dart point and ending at the points we just drew. These are the legs of the dart.

9. Fold the pattern piece along the dart center and the upper dart leg, making the dart legs meet, so that the triangle we just drew is no longer visible. You can temporarily tape down the folded dart to keep it in place.

10. Now that the dart is folded, the side seam will no longer form one smooth line. Redraw the side seam to blend the lines together. For straight side seams, draw a new straight line between the top and bottom of the side seam. For curved side seams, mimic the original shape of the side seam (you can use a French curve as a guide).

11. Now cut out your pattern piece along the new side seam. 

12. Remove the tape and open up the dart. Trace over the dart center and legs again so that the lines reach the new side seam. You have now finished drafting your dart!

13. (If you're using a pattern that is cut on the fold, along the center front line, you can skip this step.) Copy the dart and side seam to the other side of your bodice, so both sides of the bodice are symmetrical. An easy way to do this is to fold the bodice piece in half, along the center front marked by the CF notch, and trace the side seam and dart markings.

14. Cut out the rest of your pattern piece. Your altered bodice pattern is now ready to use!

 

Sewing the darts

(If you want to check the fit of the new bodice piece, I recommend sewing a toile first before cutting out the pattern in your nice fabric.)

1. Using your new altered pattern piece, cut out the bodice front piece in your fabric of choice. Make sure to transfer all notches and dart lines.

2. Fold along the center dart line, right sides of the fabric facing, and match up the dart legs. Press or pin in place.

3. Starting at a side seam, sew a straight stitch along the dart legs until you reach the dart point. Do not backstitch at the end of your stitch.

4. Carefully pull both thread tails to the wrong side of the fabric, and secure by handknotting them together a few times.

5. Press the dart towards the top of the bodice.

6. Repeat steps 1-5 for the other bust dart.

7. If your pattern has a lined bodice, you also have to add the darts to the lining. Cut out your lining using the same altered bodice pattern and repeat steps 1-6 for the lining.

You have now successfully added darts to your bodice! Continue putting your garment together by following the instructions in your sewing pattern of choice.

 

Further improving the fit of the darts

Depending on the original pattern, the size and placement of your dart, and the fit you want, you might want to tweak the dart further. I recommend first sewing a toile to check the fit, and then making adjustments if necessary.

Some potential futher adjustments:

• The wider the dart, the more length you take away from the armhole. If you find that the bodice has become too short, add some length to the bodice piece and then redraw your dart. You can add length by drawing a horizontal line on the bodice, about halfway along the armhole side seam. Cut the bodice in two along this line and tape some pattern paper beneath to add length. Then redraw the side seams.
• Wider darts give a narrower fit. If you want a looser fit (e.g. to layer bulkier clothes beneath your garment), use a smaller dart width.
• These instructions show how to add 1 dart along the side seam. As cup sizes increase and the dart width becomes wider, the dart becomes sharper/pointier around the bust. If you find that your dart is too pointy, you can divide the dart width over 2 darts, adding one at the side seam and one at the waist. I recommend the slash and spread method for transfering darts to do this.