The Colorado Hairstreak stamp features a stylized purple butterfly, the state insect of Colorado. Its square design carries the nonmachinable surcharge inscription. USPS issued this design on March 9, 2021, for letters that require nonmachinable postage.
Mailing use
This nondenominated stamp pays the applicable USPS domestic nonmachinable 1-ounce letter rate, including the nonmachinable surcharge. It is intended for eligible letters that cannot be processed by sorting machines, such as certain square envelopes. Heavier letters and other mail classes may require additional postage.
