1888 Jacobi’s Printers' Vocabulary / O / Official envelopes. [p. 90]
Long narrow envelopes, 8¼ × 3¾ inches, to take fcap. folio when folded in four—used in official circles.
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ABCDEFGHIJKLMNOPQRSTUVWXYZ
Entry taken from Printers' Vocabulary, by Charles Thomas Jacobi, 1888.
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