Around the world there are many examples of the so called “Postmaster rouletting” where local postmasters rouletted former imperforated stamps. Todays stamp is an example from USA: “
After the need for imperforate sheets of 400 of the 1912 1-cent and 2-cent Washington Franklin series in vending machines ended, Kansas City’s postmaster faced a dilemma. He could return the small surplus to Washington, DC, for redemption or he could make them available to patrons over-the-counter. He decided to roulette the stamps using tracing wheels and add them to the sales stock. This created the local perforations that collectors today identify as the “Kansas City Roulettes.”