Present your poster design using this cool mockup, The A3 size print measures 29.7 x 42.0 cm or 11.69 x 16.53 inches. You can easily put your poster design in the mockup, if this is your first time using a photoshop mockup, head over to youtube and search for a mockup tutorial and it will guide you to do it.
Created by: Qeaql
Format: Layered PSD
Requires: Photoshop CS4+
This mockup is created by Qeaql Team, they are one of the best mockup creators and have several premium offerings which you can check out at Qeaql Store at CreativeMarket