Bag Pattern Cutting

Bag grading is fundamentally different from apparel grading. Apparel grows around a body; a bag grows around a capacity target. A 40 L duffel graded up to 60 L doesn't just get taller — depth, length and gusset width all grow proportionally to hit the litre target.

• Length grade — 60–80 mm between adjacent sizes on duffels.
• Depth grade — 40–60 mm; gusset panels grow the most.
• Height grade — 30–50 mm; kept smaller to preserve silhouette.
• Strap and pocket panels rarely grade — a 15 mm webbing is 15 mm across all sizes.

Once patterns are graded, a CAD operator lays them out on a marker (a printed plan of the cutting layout). A well-nested marker interlocks curves and rotates panels to fill white space.

• Random-run marker — mixes all sizes on one lay; best yield.
• Size-block marker — one size per lay; simpler to sort but 2–3% lower yield.
• Directional panels (logo prints, engineered graphics) must lock rotation, which drops yield by 4–6%.

A clicker press is a hydraulic press with a steel-rule die shaped like the panel. The die stamps identical panels from a stacked lay in one stroke.

• Die cost — USD 40–120 per panel, amortised over the production run.
• Tolerance — ±0.5 mm, tighter than knife cutting.
• Best for — main body, side gusset and bottom panels on high-volume standard styles.
• Not for — engineered graphic panels where the print orientation must be tracked.

A vertical reciprocating knife follows a marker paper glued to a stacked lay. The operator steers the knife along every panel line.

• Lay height — up to 40 plies of laminated fabric, higher for lighter mesh.
• Tolerance — ±1.5 mm, operator dependent.
• Best for — engineered panels, low-volume runs, prototype work.
• Notching — a rotary notcher cuts triangular marks at match points before the lay is broken down.

Every bundle leaving the cutting room carries a ticket with style, size, panel name and lay position. Random panels are pulled and measured against the master pattern.

• Panel measure — ±1.5 mm on knife cuts, ±0.5 mm on die cuts.
• Notch verification — missing notches send the bundle back to re-cut.
• Fabric shade lot — bundles from different rolls are separated so no single bag mixes shades.