I claim the ornamental design for a wallcovering border, as shown and described.
FIG. 1 is a top plan view of the wallcovering border of the invention, showing my new design; the bottom plan view being flat and unornamented.
FIG. 2 is a lower edge elevation view of the wallcovering border of the invention; the upper edge elevation view being a mirror image thereof.
FIG. 3 is a left end elevation view of the wallcovering border of the invention; and,
FIG. 4 is a right end elevation view of the wallcovering border of the invention.
The wallcovering border of the invention comprises an elongate flat strip with transparent pouches symmetrically arrayed on the top face. The bottom face is flat and unornamented. The figures shown in broken lines in FIG. 1 illustrate decorative figures that might optionally be applied to the top face of the wallcovering border, but are not claimed. The broken ends of the wallcovering border in FIG. 1 indicate a wallcovering border of indeterminate length.