Even if you don’t normally indulge in impulse purchases, you might want to make an exception: Wednesday, June 10, is your last chance to order customized stamps.

As Lifehacker reports, the U.S. Postal Service (USPS) is terminating its program with PhotoStamps, an online store that allows you to upload your own image—which could be anything from a photo of your very good dog to a scan of your toddler’s latest finger-painted masterpiece—to a sheet of stamps.

Since the USPS hasn’t announced plans to replace the program with something similar, it could be your last chance to stock up on personalized postage for the foreseeable future. A sheet of 20 customized first-class stamps costs $26, and they’ll still be valid to use after the program ends. If you don’t have an image in mind, there’s a wide selection of other stamps available on the site, themed for holidays, weddings, and many other special occasions.

The only stamps that’ll be available to purchase through PhotoStamps after June 10 are the Last Week Tonight With John Oliver stamps, which the HBO show launched in May as a way to support the USPS, whose funding comes solely from the sale of postage and other products—not from taxpayer dollars, like so many of its fellow government organizations. Each 20-stamp sheet, featuring recurring characters from the show, costs $14, and PhotoStamps will continue selling them through Monday, June 15 (or while supplies last).

While you wait for your stamps to ship, here are 12 things you should know about the USPS.

[h/t Lifehacker]