Tiger Rugs
Both double and single mesh canvases are obtainable in any length and in various widths between the "selvedges" (i.e. the finished edgings of extra close warp threads where the weft threads stop and double back on themselves).
The range of widths starts at 12 inches and 48 inches is the maximum except on very rare occasions, and not all canvases can be bought in all widths.
As with wool, it is wise to ask for patterns before ordering canvas.