The bust point is the most prominent point of the bust. It is the pivot every dart is rotated around.
It is a point, not a line, and it sits inside the piece. PatternScan Pro captures the outline, so the bust point is not in the file by itself. Add it in the vector program or in pattern CAD where the darts are worked on.

Digitize sewing patterns without tracing.
Test PatternScan Pro free for 14 days with the full feature set. You need your smartphone, a printer and one pattern you always wanted digital.