The ornamental design for a mask for a cabinetdoor opening, as shown and described.
FIG. 1 is a perspective view of a mask for cabinet door opening in use condition.
FIG. 2 is a front elevational view of the mask for cabinet door opening.
FIG. 3 is a rear elevational view thereof.
FIG. 4 is a top plan view thereof.
FIG. 5 is a bottom plan view thereof.
FIG. 6 is a right side elevational view thereof; and,
FIG. 7 is a left side elevational view thereof.
The broken line showing of a portion of a rear of the mask for cabinet door opening forms no part of the claimed design. The broken line showing of a cabinet door illustrates the environment of the claimed design and forms no part thereof.