The ornamental design for a canvaswatchband, as shown and described.
FIG. 1 is an isometric view of the canvas watch band;
FIG. 2 is a top plan view of the canvas watch band;
FIG. 3 is a left side elevation view of the canvas watch band, with the right side elevation view being the same;
FIG. 4 is a bottom plan view of the canvas watch band;
FIG. 5 is a front elevation view of the canvas watch band; and,
FIG. 6 is a back elevation view of the canvas watch band.
The broken lines in the drawing illustrate environmental structure that forms no part of the claimed design. The illustrated stitching pattern forms part of the claimed design. The cross-hatching shading in the figures is fragmentarily shown for convenience of illustration, it being understood that the cross-hatching shading is uniformly continued over the surface on which it appears.