Indeed Pre-Printed / Write On Label Auxiliary Label Yellow Paper Date Opened Exp. Date Initial Black Quality Control Label 5/8 X 1-1/2 Inch (786013_PK) 1000/PK1 1 2 x 5 8 inch labels are yellow with black text that reads Date Opened, Exp. Date, Initials. Recording the expiration date ensures items are not used when they're no longer effective or perhaps even dangerous. There are 1,000 labels per package so you should have enough to keep track of many things you encounter daily, e. g. food and medicine.