The ornamental design for a napkin with pattern, as shown and described.
FIG. 1 is a front view of a napkin with pattern showing our new design; and,
FIG. 2 is a front view thereof in a folded configuration.
The dash dot dot dash broken lines surrounding FIG. 1 depict the boundaries of the claim and form no part thereof. The dash dot dot dash broken lines around and within FIG. 2 are a second view of the boundaries found in FIG. 1 and form no part of the claim. The dash dot dash broken lines within FIGS. 1 and 2 which illustrate curved and straight lines depict portions of the napkin with pattern that form no part of the claimed design. None of the described broken lines are included in the claim.