Sewing patterns for CLO 3D, Gerber and Lectra: AAMA DXF explained

Pattern software like CLO 3D, Gerber, Lectra and Optitex reads patterns from DXF files, but not every DXF. Here is what an AAMA DXF holds, why it matters, and how to bring a pattern into CLO 3D.

Last updated 30 October 2026

Plain DXF and AAMA DXF

DXF is a common drawing format. A plain DXF is only lines: good for Illustrator, a CAD program or a laser cutter, but pattern software sees it as a drawing, not as pattern pieces.

AAMA DXF (also called ASTM D6673) is the clothing industry's version. Each piece is stored as its own named block, and each kind of line sits on a numbered layer that pattern software understands: the cutting line, the notches, the grainline, the stitching line.

What the layers mean

Layer 1: the cutting line of the piece, with its corners as turn points (layer 2).
Layer 4: notches.
Layer 6: a fold line, for a piece cut on the fold.
Layer 7: the grainline.
Layer 8: internal lines, such as darts and placement lines.
Layer 13: drill holes.
Layer 14: the stitching line.

Importing into CLO 3D

In CLO 3D, open the import menu and choose DXF (AAMA/ASTM). Set the unit to match the file (millimetres for a Styli file) and import. Each piece arrives as a pattern piece with its notches, grainline and sewing line, ready to arrange around the avatar and sew. Menu names can change slightly between CLO versions.

Before you simulate, measure one piece with CLO's ruler to confirm the scale.

Gerber, Lectra and Optitex

They read AAMA DXF too, through their own import tools. Graded files keep each size as its own set of pieces.

DXF from Styli

Every Styli pattern downloads as AAMA DXF for pattern software and as a plain DXF for drawing programs, in millimetres. Each piece is a block named after it, with its name, quantity and size as the standard text, and graded sizes come as separate, nested sets.

Start from a sketch: how Styli drafts the pattern.