You can find our Poster format templates on the left menu:
Posters are single page works-of-art to convey information in an attention-grabbing visual.
They help to relay information and are most suitable if you plan to later print your work to paper.
For Poster templates, there is no semi-transparent line to adjust the height at the end of the block, so you'll use the Settings tab on each block's left border for this.
If you change one block to be A4, for example, or if you change one block to be 800 px to 600 px, the size set will apply to ALL blocks.