The ornamental design for a high visibilitysheetmaterial, as shown and described.
FIG. 1 is a front view of a high visibility sheet material showing my new design.
FIG. 2 is a side elevation view thereof, an opposite side view being identical;
FIG. 3 is a perspective view thereof; and,
FIG. 4 is a rear view thereof.
The oblique lines on parts of the design shown in FIGS. 1 and 3 indicate the reflective quality of these elements on the front of the design. The figures show two symbolic breaks along the length of the design drawn in dot dash dot broken lines. The break lines and portions of the article between the break lines form no part of the claimed design. The dot dash dot break lines and the broken lines at the top and bottom edges of the figures depict the boundaries of the claim and form no part thereof.