Learn to Adjust the Bust Apex on a Pattern

In this article, we’ll show you how to adjust the bust apex on a sewing pattern, so it matches your measurements. Most women don’t like to sew for themselves because it is hard to fit when you have curves. So if you are also one of these women, then you no longer need to worry about this, as we’ll help you to learn how to adjust the bust apex on a pattern, so you make it match your own measurements. There are a few basic concepts that you need to learn.

An important concept is where the bust apex is on your pattern. The bust apex refers to the most protuberant point of the bust on each side of the body. It also corresponds approximately to the point where the nipple is, although it may be slightly higher, lower or to the side of the nipple, depending on the individual shape or bra. The bust apex is also referred to as the bust point.

How to measure

It is important to acknowledge that the sewing patterns should be changed to fit your body, so you can’t expect the patterns to fit you perfectly. As you probably know, drafting is done based on average measurements, so there is almost no pattern to fit every measurement.

When you want to measure your bust apex height, you are recommended to wear a shirt with a shoulder seam that sits centered on your shoulder. Another thing that is helpful is wearing the bra that you would most likely wear with the pattern you are going to sew. Measure from the shoulder seam to your bust point. The bra plays an important role in this measuring because some bras will raise your bust apex. Also, not wearing a bra is likely to give you a lower measurement.

Also, many bodies require width adjustments to the bust apex on the pattern. To make sure everything is fine, you should take a horizontal measurement from center front to your bust point, once you have located your bust point.

How to find the bust apex on your pattern

Now let’s see how to find the bust apex on a pattern. In the case your pattern has multiple darts, extend the line through their centers. The bust apex is where they cross. In the case your pattern has princess seams, the bust apex is given by the deepest part of the curve on both the center front and the side front.

In case your pattern only has one dart and you know what cup size it is drafted for, you can simply draw a circle with the required diameters and align the circle’s edge on the dart tip at the center of the circle on the extended line, so you will find the apex.

Once you found the bust apex on your pattern, you can now go on and compare that to your own bust apex. Doing this helps you to find out whether you need to lower or raise it, or shorten or lengthen it.

How to raise or lower a side seam or armscye dart

First of all, mark the original dart onto another piece of paper. You are recommended to use a dark marker for this, as it will show up if you place the paper under the pattern. After you did this, measure from the shoulder of the pattern and from the center front, so you will mark where your bust apex is. Move your traced dart up or down, to point it at your apex. Retrace the new dart and redraw the seams, to make them align your new dart.

How to raise or lower bust apex on princess seams

Create an upside down L shape by drawing a horizontal line and a vertical line. Line up your pattern with the top of the shoulder touching the horizontal line and the bust curve touching the vertical line. Measure from the horizontal line down the amount of the height of your bust apex plus the pattern’s seam allowance. Mark the point where you need the fullness to hit, by marking along the vertical line.

Mark around your pattern piece’s top, and turn the piece up or down, to make the fullest part of the curve match your mark for the fullest point. Mark the area around the curve and blend back to the original pattern shape at the pattern’s bottom. Do this step for both the side front and center front.

How to shorten or lengthen a side dart

It is possible that your bust points are closer together or further apart than the pattern. In this case, you need to redraw the darts so that they point to where your apex is widthwise. For this, you need to start by making any dart height adjustment. Now mark you bust apex on the pattern. Based on your cup size, determine how far the dart point should be from the bust apex. Using your apex, draw a circle as the center and continue by redrawing the dart legs to make the point of the dart hit the outer edge of your circle, while it is still pointing at your apex.

How to adjust apex width if there are waist or shoulder darts

Mark the original darts onto a different piece of paper, and continue by measuring from the shoulder of the pattern and from the center front to mark where your bust apex is. Move your marked darts left or right, until the points are pointing at your apex. Re-mark the new darts and redraw the seams to align with the new darts.

How to adjust apex width with princess seams

To do this, you actually need to move seamlines. Depending on the style lines, a princess seamed bodice’s seam should pass right through, or at the edge of your bust apex. Measure from the center front of the pattern, so you can mark where your bust apex is. For a wider apex to apex measurement, you need to slash and spread the center front. For a narrower apex to apex measurement, you need to overlap it and redraw the curve. No matter which of these you need to do, you’ll need to do the opposite to the side front, to keep the pattern’s overall circumference the same.

When to do a bust apex adjustment

Now let’s see when in the fitting process you need to do the bust apex adjustment. During the fitting process, you need to first ensure that the pattern will fit around you, and then fit from the top down. This means that on a bodice, you follow these steps: shoulder, bust, waist. So the first thing you need to do is any small or full bust adjustments first and then lower or raise the apex. However, before you start any slashing, spreading, or overlapping for bust adjustment, you are recommended to mark out where the apex is on your pattern.