Posters - non folded a larger format informational advertising, usually with one-sided or double sided printing.
The size, color  and thickness of the paper may be freely chosen.

A standard flyers formats:
A4 – 210x297 mm
A3 – 297x420 mm
A2 – 420x594 mm

B used in printing formats:
B4 – 243x350 mm
B3 – 350x490 mm
B2 – 490x700 mm

For Press release prepare files as for final pages size, plus 2 mm bleeds at edges for trimming.