Carson Dellosa Colorful Chalkboard Straight Borders (108197) Straight edges for easy use and continuity of design. This stylish border is fun to use as window, door, or locker decorations. Versatile enough to stay up in the classroom all year! Each set includes 12 strips that measure 3' x 3" for a total of 36' Their straight edges are perfect for continuity, and their new two-sided design makes it easier than ever to coordinate your whole classroom.