9.1.2. DXF ASTM File Format¶
- ASTM D6673-10 Standard Practice for Sewn Products Pattern Data Interchange-Data Format (Withdrawn 2019)
ASTM D6673-10 is based on AutoCAD DXF version R13.
Each ASTM file contains:
- DXF file header, one pattern style per file;
- DXF entities. In DXF terms an entity can be a line, polyline, point, text, etc.;
- Layers to separate DXF information by type and function. Detail information is assigned to one of 23 pre-defined layers and a variety of DXF entities;
- Style System text that is common to all pieces in the pattern and is placed once;
- Pattern pieces. ASTM uses DXF blocks, which contain graphical and textual information, to define a piece. One block per pattern piece;
- Piece System Text that describes each pattern piece and is part of a block;
- Annotation, part of a block, to clarify instructions for production;
- Instructions for further processing for the purpose of grading, nesting, cutting, etc.
ASTM defines 23 layers for the differentiation of information:
Layer Definition Purpose 1 Piece boundary Outline of each pattern piece and style system text 2 Turn points Turn points for layers 1, 8, 11, 14 3 Curve points Curve points for layers 1, 8, 11, 14 4 Notches; V-notch and slit-notch; alignment. Articulation of molding; I-shape or V-shape: alignment pieces 5 Grade reference and alternate grade reference line(s) Grading 6 Mirror line Symmetry of fold 7 Grain line Direction of fabric grain 8 Internal line(s) Graphic annotation of placement. Not cut. 9 Stripe reference line(s) Fabric alignment of stripes 10 Plaid reference line(s) Fabric alignment of chequers 11 Internal cutouts(s) Cutline inside of outline 12 Intentionally left blank 13 Drill holes Punch markers 14 Sew line(s) Line(s) indicate where to stitch 15 Annotation text Annotation, not style system text (1) or piece system text (1) 80 T-notch T-shape: slit with T-branch at end of notch 81 Castle notch U-shape: equal width, rectangular at end of notch 82 Check notch V-pointed notch, left or right side perpendicular to boundary 83 U-notch U-shape: equal width, semi-circle at end of notch 84 Piece boundary quality validation curves ASTM: Mandatory system information for polyline(s) layer 1 85 Internal lines quality validation curves ASTM: Mandatory system information for polyline(s) layer 8 86 Internal cutouts quality validation curves ASTM: Mandatory system information for polyline(s) layer 11 87 Sew lines quality validation curves ASTM: Mandatory system information for polyline(s) layer 14
- Layer 0 is not in use.
- Layers must be numbered, not named textually.
ASTM recognizes points for the purpose of:
Point Layer Function Turn points 2 Turn points for piece boundary (1), internal lines (8), internal cutouts (11), sew lines (14) Curve points 3 Curve points for piece boundary (1), internal lines (8), internal cutouts (11), sew lines (14) Notches 4 Slit and V-notches definition Grading 5 Grade reference location Stripes 9 Stripe match points for alignment (optional) Plaids 10 Plaid match points for alignment (optional) Drill holes 13 Punch marker location and definition T-notch 80 T-notch definition Castle-notch 81 Castle-notch definition Check-notch 82 Check-notch definition U-notch 83 U-notch definition
ASTM uses the DXF block structure to group all elements of a pattern piece.