The ornamental design for a cuppaintgun, as shown.
FIG. 1 is a perspective view of a first embodiment a cup paint gun of the present invention.
FIG. 2 is a left side view of the cup paint gun of FIG. 1.
FIG. 3 is a right side view of the cup paint gun of FIG. 1.
FIG. 4 is a front view of the cup paint gun of FIG. 1.
FIG. 5 is a rear view of the cup paint gun of FIG. 1.
FIG. 6 is a top view of the cup paint gun of FIG. 1; and,
FIG. 7 is a bottom view of the cup paint gun of FIG. 1.
The broken line showing of the power cord is included for the purpose of illustrating portions of the paint gun and forms no part of the claimed design.