The ornamental new design for a paintbrushattachment, as shown and described.
FIG. 1 is a perspective front view of a new design for a paint brush attachment in accordance with the presently disclosed design, the dotted line showing of a paint brush does not form a part of the claimed design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof, the dotted line showing of a magnetic base not forming part of the claimed design;
FIG. 4 is an exploded perspective view showing the magnetically attached shield;
FIG. 5 is an exploded perspective view showing an alternative shaped magnetically attached shield;
FIG. 6 is a top elevation view thereof;
FIG. 7 is a bottom elevation view thereof;
FIG. 8 is a right-side elevation view showing the shield in its raised position, the left side being a mirror image thereof; and,
FIG. 9 is a right-side elevation view showing the shield in its lowered position, the left side being a mirror image thereof.