Gillette's original razor patent was due to expire in November 1921 and to stay ahead of an upcoming competition, the company introduced the New Improved Gillette Safety Razor in spring 1921 and switched to the razor and blades pricing structure the company is known for today. While the New Improved razor was sold for $5 () – the selling price of the previous razor – the original razor was renamed to the Old Type and sold in inexpensive packaging as "Brownies" for $1 (). While some Old Type models were still sold in various kinds of packaging for an average price of $3.50, the Brownie razors made a Gillette much more affordable for the average person and expanded the company's blade market significantly. From 1917 to 1925, Gillette's unit sales increased tenfold. The company also expanded its overseas operations right after the war by opening a manufacturing plant in Slough, near London, to build New Improved razors, and setting up dozens of offices and subsidiaries in Europe and other parts of the world.