What is Canvas?

Canvas is a heavy, closely woven fabric in plain weave. The Random House dictionary describes canvas as a closely woven heavy cloth made of cotton, hemp or linen and used for tents and sails; Collins also lists jute among the fibers. Canvas names a structure and weight, not a fiber: the same name is used for cotton, linen or hemp canvas. The painting surface is another meaning of the word. In Turkish, the surface painters paint on is the dictionary entry tuval; the Turkish Language Association (TDK) dictionary has no entry for kanvas.

Canvas structure and fiber

CottonWorks lists canvas among the common fabrics woven in plain weave, and the Pratt Institute also names canvas among plain-weave examples. In plain weave each warp yarn passes over one weft yarn and under the next. The many binding points make the fabric stiff and not very drapey, but very stable: skew, seam slippage, yarn pulling and snagging are rare problems (CottonWorks). Plain-weave fabric does not stretch unless elastic yarn is added (Pratt Institute).

The fiber varies by source. Textile Research Centre Leiden (TRC Needles) describes canvas as a strong, firm, machine-made fabric, made mostly of cotton, linen or occasionally silk, and says it is produced in many qualities and grades, from softly finished to heavily sized (starched). So the name “canvas” alone does not tell you the fiber content, weight or finish.

Weight: the numbered duck system

Heavy, closely woven cotton canvas is also called “duck” in English. An encyclopedia entry divides canvas into two basic types, plain and the more tightly woven duck, and says that in the US grading system a higher number means a lighter canvas (Wikipedia). The document behind this system is a 1924 study of the US Bureau of Standards (Schoffstall and Fisher). It defines numbered duck as a mechanical cotton fabric woven in plain weave from heavy plied yarns. The number is calculated as 19 minus the weight in ounces of a linear yard 22 inches wide, so the heavier the fabric, the lower the number. Examples from the specification's table for hard-woven duck:

The g/m² values are calculated with 1 oz/yd² = 33.906 g/m² (NIST SP 811). This is a 1924 US specification: take the weight of today's products from the manufacturer's technical data sheet and from measurement, not from the table. To convert between oz/yd² and g/m², use the fabric GSM calculator.

Uses

The Bureau of Standards study lists these uses for numbered duck: pontoon covers, tarpaulins, tent parts, shades and awnings, hammocks and bags; it adds that the close weave makes duck easy to waterproof. Dictionaries define canvas as a fabric used for tents and sails, and TRC Needles also names tarpaulins, painting canvas and sailmaking. An encyclopedia entry also lists bags, backpacks and shoes (Wikipedia).

Canvas and similar fabrics

What to specify when sourcing canvas

1. Fiber, with percentages: cotton, linen, hemp and blends do not behave alike.
2. Weight in g/m², with the test method: mass per unit area from a small sample is measured to EN 12127, and for woven fabric to ISO 3801. If you buy rolls by weight, the fabric meter to kg calculator gives meters from width and weight.
3. Finish and water resistance, separately: is it sized, softly finished or coated? The name “canvas” says none of this.
4. Have canvas shrinkage measured: ISO 5077 for width and length change, ISO 6330 for the washing-drying conditions. The fabric shrinkage calculator gives the cut size and the fabric consumption calculator helps with order quantity.

For a comparison of woven fabric families, see the fabric types guide; for suppliers, see the Woven Fabrics category.

Frequently asked questions

Is canvas the same as denim?

No. CottonWorks lists canvas among plain-weave fabrics, and describes denim as a cotton fabric with an indigo-dyed warp and an undyed weft, usually in 2×1 or 3×1 twill.

Is canvas breathable?

Canvas does not stop sweating; sweating is how the body cools, and what the fabric contributes is taking up sweat, spreading it and leaving room for it to evaporate. The sources for this entry contain no air-permeability or water-vapor-resistance measurements for canvas. Suganthi et al. (2024), working with knitted samples, identify fabric structure, weight and thickness as the main drivers of water-vapor permeability: permeability climbs as weight and thickness fall and as the structure loosens. Dictionaries define canvas as a heavy, closely woven fabric, so it does not sit at the permeability-raising end of these factors. Still, the result varies with fiber, weight and density, and nothing can be settled without measurement. If you plan garment use, request air-permeability (EN ISO 9237) and water-vapor-resistance (EN ISO 11092) results; the reading framework is in breathable fabrics for summer.

Are canvas and duck the same?

Duck is the English name for heavy, closely woven cotton canvas. An encyclopedia entry divides canvas into plain and the denser duck, and in the US numbered duck system a higher number means a lighter fabric (Wikipedia).

Are canvas and tuval the same?

Random House gives the piece of canvas painted on as one meaning of canvas. The TDK dictionary has no entry for kanvas; its entry tuval defines the stretched coarse cloth of linen, hemp or cotton that is painted on. When you describe the fabric, say canvas; for the painting surface, say tuval (painting canvas), to reduce confusion.