A dart takes width out of a flat piece of fabric so it can wrap around a curve of the body. A wedge-shaped area is folded together and sewn along a line that tapers to a point, typically at the bust, waist, hip or shoulder.
A dart has two legs that start at the cut edge and a point where they meet. The distance between the legs at the edge is the dart intake and decides how much width is removed. The length decides how the shaping runs: a short, deep dart shapes more sharply, a long, shallow one spreads the curve over a larger area.
Legs and point are drawn on the paper pattern and transferred to the fabric with tailor's chalk, pins or a tracing wheel. You sew from the edge towards the point, and the last stitches run out close to the fold so no bubble forms at the tip. The dart is then pressed towards the centre or downwards, depending on where it sits.
A dart can be rotated around the bust point to a different position without changing the fit. A waist dart becomes a shoulder dart or a side seam dart. This is one of the basic techniques that turns a block into a style pattern.
In PatternScan Pro a dart is marked with two notches, at the two points where its legs meet the cut edge. The contour stays closed and the position of the dart is recorded in the file.

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