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Shifting Dart Location

One of the fundamental rules of pattern drafting is that darts can be shifted to almost any seam line without altering the underlying fit of the garment. Only the external shape of the pattern piece changes; the total fabric volume and shape over the body remain identical.

The most common example of dart manipulation is the front bust dart. Sloper drafts often originate with a primary dart at the waist line.

Center ArmholeShoulder PointCenter ShoulderCenter NeckCenter Front NeckCenter Front BustCenter Front WaistStandard WaistFrenchSide
Dart Locations (click to expand)

The Ten Standard Bust Dart Locations​

You can move a bust dart to any position along the outer edge of the pattern, provided the dart legs originate from a seam line and point directly to the bust apex:

  1. Standard Waist
  2. French (angled from the lower side seam toward the waist)
  3. Side (underarm side seam)
  4. Center Armhole
  5. Shoulder Point (armhole/shoulder intersection)
  6. Center Shoulder
  7. Center Neck
  8. Center Front Neck
  9. Center Front Bust
  10. Center Front Waist

The Two Apex Points: Working vs. Stitching​

Before shifting a dart, it is critical to understand the difference between the Working Apex and the Stitching Apex:

  • Working Apex (Bust Point): The exact anatomical point of the bust mound. All pattern slashing, pivoting, and rotating must anchor at this precise point to keep the geometry true.
  • Stitching Apex: Sewing a dart directly to the working apex creates a sharp, conical pucker that does not match natural body contours. To create smooth, rounded fullness, the final stitching line ends short of the working apex.
tip

Keep all original darts pointing directly to the working apex on your master sloper. When finalizing your ready-to-sew garment pattern, back the dart tip off by 0.5” (13 mm) to 1” (25 mm) from the working apex. PatternMaker Pro can create this new stitching dart for you using the Stitching Dart tool.

Understanding the Slash & Rotate Method​

The Slash & Rotate method is a very common way to move fullness from one part of the pattern to another. The key to understanding the process is the rotational block definition. The rotational block is defined as the area between a leg of the original dart and the new slash point on the pattern edge. Both lines terminate at the bust apex, which becomes the pivot of the rotation.

In most cases, you will want to keep your center lines vertical, so the block will be defined on the side away from center front. This keeps your center lines in position, preserving the straight of grain, and rotates the rest of the pattern.

Below you can see an illustration of a front bodice. The new slash point is mid-shoulder. The block is defined from that slash all the way down to the outer dart leg in the old dart.

Front Bodice Slash Point (click to expand)

Here is another image that shows that block rotated counter-clockwise to close the waist dart and open the shoulder dart. The original dart was closed completely, so the legs meet and touch. All of the dart volume has been moved to the shoulder. Note that the center line has not been tilted or changed. Also, the dart apex is exactly the same for both darts. This is important to retain the sizing and fit regardless of where the dart is located.

Front Bodice Dart Rotation (click to expand)

How to Move a Dart​

To shift a single dart from its original position (e.g., Standard Waist) to a new location (e.g., Center Shoulder):

  1. Mark the New Position: Mark your target point on the outer seam allowance or pattern edge (Center Shoulder).
  2. Slash to the Apex: Cut along a straight line from your new mark directly to the working apex.
  3. Slash the Original Dart: Cut along one leg of the original waist dart, stopping right at the working apex (leave a tiny paper hinge at the apex so the pieces stay connected).
  4. Rotate & Close: Pivot the slashed section counter-clockwise until the original waist dart legs overlap completely and lie flat. Tape the old dart closed.
  5. Form the New Dart: Your new dart will automatically open up at the Center Shoulder.
warning

The dart width at the waist before the rotation and the dart width at the shoulder will not be the same. The waist dart and shoulder dart are different distances from the apex, which results in different dart widths. Just be assured that the fullness has been transferred correctly.

Folding & Finishing​

Once a dart has been shifted to its new location, finish the pattern with these two key rules:

  • Folding Direction: Vertical darts fold and press toward Center Front or Center Back. Horizontal and diagonal side darts fold and press downward.
  • Truing the Seam Line: Fold the new dart closed on your paper in its final pressing direction before cutting along the outer seam allowance. This automatically generates the correct roof/turnback shape at the edge so the seam lies perfectly flat when sewn.

Splitting Dart Intake​

You do not have to move 100% of a dart to a single new location. If a full bust dart produces a wide, prominent dart, you can split the volume. By rotating the pattern halfway, you can leave 50% of the intake at the waist and shift 50% to the shoulder or side seam, distributing the fabric shaping more subtly across the torso.

Bust Dart 50%, Shoulder Dart 50% (click to expand)

Multiple Locations​

You can also use this technique to move a dart, in full or in part, to multiple locations. In this image the dart at the waist was transferred to three new slash points at the center front. This type of change can be a little tricky with paper because you'll want an even division between the new slash points.

Bust Dart Moved to 3 Darts at Center Front (click to expand)

Working with PatternMaker Pro​

This process is greatly simplified in PatternMaker Pro. When you create a dart, you register it with the system. Then you can manipulate it using one of the many automatic dart manipulation tools:

If you aren't working with a registered dart, you can still take advantage of simple slash and rotation using the Slash & Spread tool.

Quick Review​

✏️ Question #1: What is the core principle behind shifting a bust dart from one location to another?

✏️ Question #2: What is the key difference between the Working Apex and the Stitching Apex?

✏️ Question #3: Why does a shoulder dart have a different width in inches than a waist dart shifted from the exact same pattern?

✏️ Question #4: What happens if you only close a waist dart halfway during the slash-and-rotate process?