Large FBA Solution: The Y-Dart FBA

If you have a large bust, you might be familiar with the common slash-and-spread method of performing a Full Bust Adjustment (FBA) pattern alteration that adds ease to the bust area through adding or increasing the size of a bust dart. If you are not already familiar with FBAs but want to learn the basics, read through the CSC’s Beginner’s Guide: Full Bust Adjustment post.

The traditional slash-and-spread works fantastically well for most of us…up to a point. Once you increase the bust dart to a large enough size, that dart becomes rather ungainly to sew and creates an awkward flap of fabric at each side of your of your bust. To see an example of one of these Big Honkin’ Darts, see my previous post about Large FBA Issues: Dealing with the Big Honkin’ Dart. This post also gives an introduction to several options for dealing with this unwieldy dart.

One increasingly popular method of dealing with the large dart caused by a traditional FBA is to make a slight alteration to your FBA method by performing a Y-Dart FBA. I first became aware of the Y-Dart FBA when Palmer-Pletsch published this alteration in an updated revision of Fit for Real People several years back. Palmer-Pletsch recommends switching to the Y-Dart method of FBA if you’re performing an FBA larger than 1.5″ (roughly 3.8 cm) on a darted bodice. A great thing about the Y-Dart method is that it simply adds one more pattern cut to a traditional FBA, so you can start out doing a traditional FBA, and switch to the Y-Dart method, if needed.

Pros and Cons of a Y-Dart FBA

The Y-Dart FBA alteration provides a great alternative to the traditional FBA in many cases; however, this alteration isn’t a magic bullet to the Big Honkin’ Dart issue. The following list of Pros and Cons can help you decide if this alteration might be a good choice for the garment that you’re making:

Pros:

• The Y-Dart method is a good choice for large FBAs on a bodice with a bust dart (as opposed to princess seams).
• If you typically rotate all or part of your bust dart, the Y-Dart method works well for garments that do not have a logical place for dart rotation.
• This method can be done “on the fly” if you’ve started a traditional FBA and then decide that the dart is too large.

Cons:

• If you need a really large FBA (3″ or more), you’ll still have a Big Honkin’ Dart to deal with.
• Some women find that the Y-Dart adds too much fabric to the upper chest for them.

To be sure if the Y-Dart method is a good choice for you and your garment, I highly recommend making a muslin to see how this alteration works for you before you cut into your good fabric.

How to perform a Y-Dart FBA

The Y-Dart FBA really only has one additional step beyond a traditional FBA. This tutorial walks through the steps of slashing and spreading your paper pattern for this alteration on a quarter-scale bodice pattern. Note that in my demonstration, I’ve drawn in seam allowance lines and will include dealing with seam allowances in my instructions.

To perform a Y-Dart FBA:

1. Let’s start by drawing in the lines that we’d normally draw for an FBA on a darted bodice:
   
2. For the Y-Dart FBA, however, we’re going to add one more line. This line will run from the middle of the should seam to the bust apex:
3. Perform the following cuts to your pattern piece:
   1. From the bottom of the pattern piece to the bust apex, pivot slightly and continue on the leg that goes to the armscye. Cut to the stitching line at the armscye, then make a snip from the seam allowance on the armscye to this point. This snip will enable you to pivot the pattern piece at the armscye.
   2. Cut from the edge of the bust dart nearly all of the way to the bust apex. Stop just short of where the previous cut passed through.
   3. Cut from the bust apex up the line towards the shoulder, stopping at the stitching line. Snip from the seam allowance to just short of this cut so that you’ll be able to pivot the piece at this point. If you’ve made all of your cuts correctly, the center of the pattern piece should now very roughly resemble a “Y”, which is how this alteration gets its name:
   4. Cut all of the way through the horizontal lengthen line at the lower right.
4. Just below the bust apex, spread the pattern pieces the amount necessary for your FBA.
   
5. Fill in the open areas with pattern tissue.
6. True up the lower-right corner piece with the rest of the bodice.
   

Let’s look at the difference between a 3″ traditional FBA and the 3″ Y-dart FBA that we just completed. Note how much more reasonable the side bust dart appears and how more gently curved the armscye is on the Y-dart pieces:

As you can see, performing a Y-Dart FBA really isn’t much more complicated than performing a traditional FBA. Have you ever tried a Y-Dart alteration? How did it work out for you?

In one more upcoming post in this series, I’m going to present one more option for dealing with the Big Honkin’ Dart caused by a large FBA: dart rotation. We’ll look at the various options for dart rotation and work through a tutorial where we’ll rotate a bust dart to another location on a bodice pattern.