The ornamental design for a tartan, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided to the Office upon request and payment of the necessary fee.
The sole FIGURE is a top plan view of a tartan showing my new design.
The tartan is shown with symbolic breaks in its length and width. The appearance of any portion of the article between the break lines forms no part of the claimed design. The outer broken line perimeter depicts the boundaries of the claim and forms no part thereof.