This Canadian postal stationery envelope features the modernist “bars” design in shades of blue and green, originally issued with an imprinted 12¢ denomination. It carries a surcharge “NEW VALUE / NOUVELLE VALEUR 15” overprint, reflecting a postal rate adjustment. The design was part of Canada Post’s promotion of the postal code system, with reminders such as “Code it… Post it!” printed on the back flap in both English and French. These envelopes were widely used in the 1970s during the transition to standardized postal code usage in Canada. Collectors value them for their bilingual overprint and role in Canada’s postal modernization.