FIG. 1 is a top-rear-left perspective view of a base cap for a wig, showing my design;
FIG. 2 is a rear-left perspective view thereof;
FIG. 3 is a front-right perspective view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a rear view thereof; and,
FIG. 7 is a top view thereof.
The broken line outline of the partial human figure assists in illustrating how the base cap for a wig may appear when in a position of use, but forms no part of the claimed design. The dash-dot broken lines in the figures depict features of the base cap for a wig that form no part of the claimed design.