Organize books, study materials and more Designed for use with ballpoint pens, pencils and permanent markers. Extra-thick tab design helps ensure durability, so you can remove and reuse the tabs easily. Self-adhesive tabs stick securely to textbooks, paper and more and remove cleanly without leaving behind residue. Post-it(R) Durable Index Tabs, 1in. x 1 1/2in., Green/Orange/Pink, 12 Flags Per Pad, Pack Of 36 is one of many available through Office Depot. Made by Post-it.