French 10 centimes Encased Postage Stamp (American Optical)

France · 1920 · 10 centimes

The reverse side of this encased postage stamp features advertising text for American Optical at 3, Boulevard Montmartre in Paris, surrounding a central opening that would reveal a 10 centimes French Sower stamp.

This encased postage stamp served as 'necessity money' during a period of coin shortage in France around 1920, likely following World War I. It also functioned as an advertisement for American Optical.