Canvas & duck for bags

Canvas and duck are both heavy plain weaves, and the terms overlap in trade use. What actually separates one quality from another here is weight, yarn thickness and whether the cloth is single- or plied-yarn. Plied yarns give a firmer, more abrasion-resistant cloth at the same weight, which is what you want for a base panel or a strap-bearing seam. Lighter canvas is easier to sew and better for a soft tote; heavier duck holds a structured shape without an added stiffener.

For bags the practical question is usually how much body you want before interlining. Getting that from a swatch is far more reliable than getting it from a GSM figure.

Useful detail: the bag type and which panels the fabric is for, whether it needs to hold structure unsupported, the finish you want (natural, dyed, waxed or coated), and your quantity for sampling and bulk. Tell us if hardware will be riveted through the cloth — that pushes the specification towards plied yarns.

Heavier canvas sits in the 160 GSM-and-above dyeing band, where a fresh colour starts at 3,000 m per colour. Natural and available shades avoid that step entirely, which is often the faster route for a first production run.