This is a poster I created for my Lego themed classroom. You can print it in color if you like the white in the middle. I printed it on yellow paper so that the entire poster was yellow and black. (I'll post a picture of the one I made soon!)
To print as a poster:
1. Click File, then Print.
2. Select "Fit" option to make sure it is full sized.
3. Select "Poster" option.
4. Adjust "Tile Scale" percentage to make it as big as you want. (I put mine at 200% and it comes out to four sheets of paper.)