Shifting Dart Location
A bust dart can move to almost any edge of the pattern without changing the fit. Only the outside shape of the piece changes. The fabric over the body stays the same.
Sloper drafts usually start with the main bust dart at the waistline, so that is where we begin.
The Ten Standard Bust Dart Locations
A bust dart can sit anywhere around the outer edge of the pattern, as long as its legs start at the edge and point straight to the bust apex. These ten locations have names you will hear in a design room:
- Standard Waist
- French (angled up from the lower side seam)
- Side (underarm side seam)
- Center Armhole (aimed at the armhole notch)
- Shoulder Point (where the armhole meets the shoulder)
- Center Shoulder (usually near the princess line)
- Center Neck
- Center Front Neck
- Center Front Bust
- Center Front Waist
Working Apex and Stitching Apex
You will hear about two apex points:
- Working Apex (Bust Point): The true bust point. Every slash and rotation anchors here, so the geometry stays true.
- Stitching Apex: A dart sewn right up to the bust point makes a sharp, cone-shaped pucker. For smooth, rounded fullness, the stitched dart stops short of the working apex.
Keep every dart on your master sloper pointing right at the working apex. When you finalize a pattern to sew, back the dart tip off by about 1/2" (13 mm) to 1" (25 mm). PatternMaker Pro can draw the new stitching dart with the Stitching Dart tool.
Slash and Rotate
Slash and rotate is a common way to move fullness from one part of the pattern to another. The rotational block is the area between one leg of the old dart and the new slash point. Both lines end at the bust apex, which is the pivot.
Usually you keep your center lines vertical, so you define the block on the side away from center front. That keeps the straight grain in place, and only the rest of the pattern rotates.
Here the new slash point is mid-shoulder. The block runs from that slash down to the outer leg of the old dart.
Next, the block is rotated counter-clockwise. That closes the waist dart completely, so its legs touch, and opens the shoulder dart. Notice that the center line has not tilted, and that both darts point at the same apex.
How to Move a Dart
To move a single dart from its original place (say, the waist) to a new one (say, center shoulder):
- Mark the New Position: Mark the target point on the edge of the pattern.
- Slash to the Apex: Cut a straight line from that mark to the working apex.
- Slash the Old Dart: Cut along one leg of the old dart, stopping at the apex. Leave a tiny paper hinge there so the pieces stay connected.
- Rotate and Close: Pivot the cut section counter-clockwise until the old dart legs meet. Tape the old dart closed.
- Check the New Dart: The new dart opens at the center shoulder.
The waist dart and the shoulder dart will not be the same width. They sit at different distances from the apex, so the same angle opens to a different width. The fullness is the same.
Make a copy of the pattern for each dart location. Stack them with a pin through the bust points and line up the dart legs. The angles all match, from the shortest dart to the longest. Tape each dart closed and stack the patterns again, and they coincide exactly.:::
Two Ways to Move It
Slash and spread (adding paper in the new opening) is slower but accurate, and easier to understand when you are new to it. Pivoting is faster and needs no cutting or taping, but the new pattern shows only the dart notches, not the stitching lines, so it fails for curved darts.
Folding and Finishing
- Pressing Direction: Vertical darts are pressed toward center front or center back. Horizontal and diagonal darts are pressed downward.
- Truing the Edge: Fold the new dart closed on your paper, in its pressing direction, before you cut the outer edge. That creates the correct point at the edge so the seam lies flat once it is sewn.
Splitting a Dart
You don't have to move all of a dart. If the full dart is wide and prominent, rotate the pattern only partway. For example, leave half the intake at the waist and move half to the shoulder or side seam. The shaping spreads more softly across the torso.
Moving a Dart to Several Places
You can also divide a dart among several new slash points. In this image the waist dart moved to three new slash points at center front. It is a little tricky on paper, because the new slash points need an even division.
Working with PatternMaker Pro
PatternMaker Pro makes this much simpler. When you create a dart, you register it with the system, and then you can move it with one of the dart tools:
If the dart isn't registered, you can still do a simple slash and rotate with the Slash & Spread tool.