What’s the Difference Between 10oz and #10 Canvas?

What’s the Difference Between 10oz and #10 Canvas?

September 19, 2018 Off By Abby Emmons

Canvas is classified in two ways: by weight (ounces per square yard) and by a graded number system (#1-12).
Why are there two different units for canvas? What is the difference between a #10 canvas and a 10 oz canvas?
We’re going to put this confusion to rest.

Picture canvas on a loom with all the strings going in one direction, and another strand going over and under each fixed strand perpendicular to it. As the fabric is formed, it’s being rolled onto a tube.

The fixed strands are called the warp of the fabric, and the strands that weaved through them are the weft -or sometimes called the woof.

The first difference between canvas in ounces and canvas in numbers is the weave style. One is a single-filled and one is a double-filled weave. Single-filled has one strand in the weft woven with one strand in the warp. Double-filled has one strand in the weft going over and under TWO strands side by side, making a stronger fabric, with particularly strong tensile strength in one direction.

Alright enough with the terminology. Guess what!? The Double-filled canvas is measured in ounces, while the single-filled canvas has the number scale. But if that were the only difference, you would expect the ounces to be much stronger and heavier than the numbered canvases, which is not the case.

While the ounce canvases are double-filled, those strings being woven are still only one string thick. Each strand in the numbered canvas is actually 3 to 5 strings twisted together. When manufacturing heavy canvases they also thicken the individual strings as well. And that adds a lot of weight.

The bigger the number, the lighter the fabric, which seems a little counter-intuitive. 😉

And there you have it! Hopefully this brings some clarity so you can pick out what you need!