Add a touch of nostalgia and charm to any job or incentive chart with Colorful Chalkboard chart seals! These self-adhesive chart seals are acid-free and lignin-free. Each pack includes 810 seals that are 3/8" in diameter. Available in a variety of colors, shapes, and designs, chart seals are an excellent addition to any teachers desk. Look for coordinating products in this design to create an exciting, cohesive classroom theme!