DXF is an exchange format for CAD drawings. In pattern making it is the common way to hand a pattern from one program to another.
PatternScan Pro writes DXF in R2013, in millimetres, with curves as polylines. A separate AAMA/ASTM export covers pattern CAD.

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.