When fitting a sewing pattern, we're accustomed to checking the standard measurements such as bust, waist and hip. What do these have in common? They are all measurements of circumference. But there's another dimension that is critical to getting a good fit: the vertical dimension.
These vertical measurements are not marked on most patterns, but you can measure and adjust your patterns in both dimensions to get a good fit and be more comfortable in the clothes you make.
So where to start? Read on to find out how to use vertical adjustment for a pristine plus-sized fit!
These two dress forms pictured above illustrate the potential need for vertical adjustment on sewing patterns.
The light pink form on the left shows how bust depth, which is the distance from the top of the shoulder to the bust apex, is considerably longer with a plus size figure or full busted figure. The horizontal line marks the bust apex on both dress forms, and that is the point on your pattern where you want the maximum fullness to accommodate the curves there.
Imagine a pattern with bust darts that would finish near that apex, closer for the less full bust and further away for the more full bust. So, based on the measuring tape, even though they may be the same height, the full busted form needs more length in the front to reach the waist.
Often wrap-style dresses or tops don’t include a side dart, so here is a way to adjust the pattern front and create the extra length that is needed.
Step 1: Evaluate the pattern
Here is the front bodice pattern piece which is a mock wrap front with shoulder darts. The bust apex is indicated on the pattern as the small circle with the +. The center front is marked and that should be transferred to your pattern, so that your wrap overlaps properly. There is no side bust dart but that will be added to create some shaping and allow for the longer front measurement from shoulder to waist.
Step 2: Make a muslin
The test version of our pattern shows that the pattern circumference is good. It appears to fit going around the body, but the issue with bodice length is clear. The yellow dots represent the bust apex on the pattern and they are about 2" higher than the actual apex of the form, which is shown by the upper ribbon.
The bodice is also pulling upwards under the bust, so the garment waist will not be in the right place.
Here's what to do next:
- Measure the distance between the pattern mark of the apex and the actual apex. This will be the distance that the pattern will be lengthen over the bust.
- Now, measure the distance between the bottom of the bodice and the waist.
- If that is more than the difference you will be adding at the bust, you may want to add a little more at the bottom edge as well, or deepen your seam allowance to permit some adjustment when you sew the top and bottom together.
Step 3: Split the pattern piece
Draw a horizontal line across the pattern, through the apex or just under as shown. Be sure that line is perpendicular to the grainline. Add a few vertical lines across this horizontal line, which are used to connect the pattern piece after you split it. Cut the pattern piece in half using this line.
Step 4: Lengthen the pattern piece
Insert paper between the now split pattern pieces, in this case we have added 2 inches across the front bodice which. Connect the vertical lines to keep everything even, including the grainline.
Step 5: Adjust the front cutting line.
By adding the 2" in the middle of the bodice, the long front edge is now a bit jagged. Smooth that edge by redraw the cutting line, splitting the difference above and below the inserted piece.
Step 6: Add a dart
With the added length the front bodice is 2" longer than the back bodice piece at the side seam. To take up that difference add a side bust dart. This kind of dart is really helpful to get a good fit on a full bust so don’t be afraid to add one where none exists.
Note that the dart point should be about 1.5" to 2" away from the bust apex. I find a dart that's slanted upward is more pleasing to the eye than one that's completely horizontal. It also helps to pin your paper pattern pieces together and test on the body, you can pinch out the extra and see just where the side dart should go. Make sure the front and back bodice seams are trued up and you are ready to try a second muslin.
Step 7: Make a muslin to test your adjustments
Here's the new muslin of this pattern, with the bodice length adjustment and a side seam bust dart added. The bottom of the bodice hits at the waist, and retains the ease and blousing of the pattern design. The new dart is creating fullness where it is needed over the bust and allowing the fabric to drape instead of pulling the waist seam upward.
Time to sew your garment!
With those adjustments the bodice drapes nicely, the soft blousing is maintained and the dress is going to be much more comfortable to wear than it would have been without the front length adjustment. And no tugging to try to get that waist seam to stay in place.
Are you going to think vertical next time you try on a muslin, and evaluate whether some added bodice length will result in a better fit? Let me know.
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