Stand for writing instruments

FIG. 1 is a top perspective view of an ornamental design for a stand for writing instruments according to the present invention;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a left side view thereof and the right side view is the same as the left side view;

FIG. 4 is a front view thereof and the back view is the same as the front view;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.