You can copy and paste images and text items across your designs opened in the PosterMyWall editor. 

Select the graphic or text item, press Ctrl-C (Cmd+C if you’re on a Mac), then go to your other design and press Ctrl-V (Cmd+V if you’re on a Mac), and you're done. 

What can be copy pasted

• Items within a design.
• Items from one of your personally created designs to another.
• Items from a personally created design to a template.
• Items from a template to your design.
• Items from one template to another.

What CANNOT be copy pasted

• Items from your computer into the Poster Maker. You have to upload them like before.