The ornamental design for a booksleeve, as shown and described.
FIG. 1 is a perspective view of a book sleeve;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right-side elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a perspective view thereof showing the invention around an opened book; and,
FIG. 9 is an enlarged perspective view thereof showing the book sleeve in use.
The dashed lines on the surface of the sleeves and shirt represent stitching and are not part of the claimed design. The broken line showing of details in FIG. 8 is included for the purpose of showing a book and in FIGS. 8 and 9 for showing a book and a cord inserted in the pocket of the book cover and forms no part of the claimed design.