Letter for advertising purposes - has two-section outer part folding along common line to inner part which has two sections with rectangular basic surface

The two sections (17,18) of the inner part (12) connect to each other along a common fold line (19), around which, as prim. fold, they are foldable towards one another. They both have a specific width (b2). To each inner section connects a sec. flat surfaced section (21,22) along the edge turned away from the prim. fold, which also has a specific width. Between the sec. flat section and the corresp. inner section (17,18) a sec. fold (23,24) is available, which is parallel to the prim. fold of the inner part and to the fold (15) of the outer part (11). Along the prim. fold (19) or in the flat area of at least one of the inner sections is a longitudinal perforation (29). To the inner sections along the prim. fold connect narrow flat strips on the inside of which is applied an adhesive coating. USE/ADVANTAGE - As a publicity letter with compact format for posting and delivery, which on receipt gradually opens out for perusal.