The ornamental design for a cover for imageplates, as shown and described.
FIG. 1 is an upper perspective view showing the top, front and left sides of a cover for image plates of our new design;
FIG. 2 is a lower perspective view showing the bottom, front and right sides thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof; and,
FIG. 5 is an upper perspective view showing the top, front and right sides thereof, with a closing flap in a different position with respect to the remainder of said design.