Ключевые слова: airmail, back, blank, clean, collection, concept, dl, document, empty, envelop, envelope, form, four, gray, heap, icon, imprint, isolated, leaflet, letter, letter carrier, mail, message, monarch, par avion, post, post office, postage, postal service, postcard, postie, postman, print, promotion, rear, set, sign, spread, stack, stamp, template, white, write,