I am cooking up a new pattern and it has a fitted bodice with waist and bust darts. So I think this is a good time to talk about moving bust darts to fit your figure.
Even women of the same height could have busts sitting at different levels. This could be because of age, cup size or just body shape.
Do I Need an Adjustment?
First, let’s talk about where the bust dart is supposed to be, otherwise, we wouldn’t know whether the bust dart needs to be moved.
Some of the patterns have the apex marked on the front. Then that’s super easy: if the apex is not where your nipple is, then you need an adjustment. Usually the apex is marked with an “X” inside a circle. Sometimes they even have the finished bust measurements written next to it.
If you have a front pattern with a waist and a bust dart, then it’s not too hard to find the apex either. At the base of each dart, you find the middle point, from there, you draw a line to the bust point, and then continue the straight line a little more. You’d find at at some point, the line from the waist dart and the line from the bust dart will meet each other. That meeting point is the apex. Again, if this apex point is not where your nipple is, you’d need to move the bust dart, and potentially the waist dart too.
If you have a front pattern only with a bust dart, but not a waist dart, then it’s not as clear where the apex is. All you know is that the bust dart point is supposed to point to the apex. Similar to the previous method, you draw a line from the mid point at the base of the dart to the dart point. Continue with this straight line, and the apex is somewhere along this line. The actual apex could be 0.5″ to 2.5″ (1.25 to 6.3 cm) or even more from the dart point along this straight line. For our purpose, if the bust dart is pointing to your nipple, then I’d say the bust dart is OK. You could still move the dart point in or out to fit your bust better, but that would be some other adjustment that we are not discussing today. For now, if it’s pointing above or below your nipple, then you’d need to move the bust dart.
With all these said, to accurately determine where your apex is, you will need to make a muslin. You can’t very well judge the positions of your apex and the pattern’s apex by putting the paper on your chest. You could maybe do some tissue fitting if you are using tissue patterns, but if you are using PDF patterns, which is likely printed on regular printing paper, then you have to make a muslin.
How Do I Move the Dart?
Here are some easy steps to move your bust dart.
First put on the pattern’s apex if it’s not already there. See above for how to find the apex. If the pattern has no waist dart, use 1″ (2.5 cm) for blouses and dresses and 2″ (5 cm)for jackets and coats from the bust point along the straight line. These are estimates.
After making a muslin, you will find out where your apex should be. For me, I am using the blue dot for the purpose of this demo. The blue dot is 5/8″ (1.6 cm) to the right of and 1/2″ (1.25 cm) higher than the original apex.
Cut out the bust dart in a rectangle (4 straight sides and 4 right angles!!). The rectangle should include the entire bust dart and it should be perpendicular to the grain line. By looking at the photo below, you may think that the upper cut line is one of the dart leg, but it actually is not if you look closely. And if yours happens to be, it’s coincidental.
I need to move my dart 5/8″ (1.6 cm) to the right and 1/2″ (1.25 cm) up. So here it is in the adjusted position.
Tape everything down and put some paper underneath to fill the gap.
Now I need to true the dart. Fold the dart as if you are sewing it. It’s going to be awkward because paper is rigid. It’s not going to be flat. Do the best you can to put the two dart legs together. For a bust dart like this, 99% of the case the dart is supposed to be pressed down, so fold accordingly.
Cut the excess paper. The side cut line should be smooth.
When you open the dart back up, your dart is trued!
If your pattern only has a bust dart, then your task is done. But if it has a waist dart too, and it’s not pointing to the apex, then you need to move the waist dart accordingly. The process is the same. You draw a rectangle that contains the waist dart.
Cut it out and move to the left or the right. In my case, I need to move it 5/8″ (1.6 cm) to the right. I cut the rectangle out.
Move 5/8″ (1.6 cm) to the right. I could also place the whole dart 1/2″ (1.25) up because the new apex is 1/2″ up. In that case I would draw the dart legs down (while maintain the same width) after backing the gap with some paper. But I decide not to do that because I like the fit there. Remember the apex could be 0.5″ to 2″ or more from the dart point, so I have some leeway. The important thing is that the dart point is pointing toward my apex, the blue dot.
Tape everything down and put paper underneath to fill the gap.
Again, I need to true the dart. Fold it as if you are sewing it. The bulk of my waist dart is usually pressed toward the side, but others might be pressed differently, so check your pattern instructions. See how awkward the fold is? It’s going to be like that and we just have to deal with it as best as we can.
Cut the bottom excess paper to true the dart. Be sure that the line is smooth when you cut.
Open the paper back up and your dart is trued!
Ta da! Here’s the pattern with darts moved to accommodate your figure.
If this is a dress and there’s a skirt below the bodice with a corresponding waist dart, you will need to move that dart too. Otherwise your two darts will not match up.
If this is a dress with no waist seam but with a fish eye dart (a fish eye dart has two dart points, one pointing up and the other pointing down, kind of look like a side way eye), then when you move the waist dart, you’d have the rectangle enclosing the entire fish eye dart and move it. You will not have to true that dart at all.
Hope this is useful!