Recently, for Blockoworld, I made 2 big advertisements with posters on them. They each used 8 print bricks pieced together to make one big picture. I have done this before in my Portal prints pack, but a lot of people asked me how to do it properly recently, so I thought I'd make this tutorial.
By Multi-Brick Prints, I mean one big printed picture made out of several smaller print bricks.
In this tutorial, I will be using one of the ads I made for Blockoworld as a refference:

First of all, you need to figure out the dimensions of your poster in Print Bricks.
This poster is
4x2 (4 Print Bricks Width X 2 Print Bricks Height)

Now we need to open an image editor. I use Adobe Photoshop. We need to create a new document to fit the
entire poster. A standard Print brick is 256x256, so we need to multiply those dimensions by how many print bricks we have.
Start a new document, and set the pixels so that it fits the following equation:
(256 x W) x (256 x H) where
W= Print Brick Width and
H= Print Brick HeightThis will give us the size of the
full poster.
In my case, I have 4 print bricks x 2 Print bricks. So my equation would look like this:
(256 x 4) x (256 x 2) which would give us a total dimension of
1024 x 512
Press OK and you will get a new blank document. Next you just have to create your print!

My print is already completed, I can't really help you with this part. Make the poster however you want!
Next we need to copy and paste each section of the poster into it's own 256x256 print so we can export it into Blockland.
If the program you are using has Guidelines, that will help with this part.
Select a 256x256 square, there are various methods to do this. Copy this selection. If your program uses layers you will need to use "Copy Merged" or something of the like.

Start a new file with the dimensions 256x256

And paste what you selected & copied from the whole poster into this file.

You will need to do this for EACH PIECE of your poster.
Save Each piece of the poster this way and all of their corresponding icons into the proper packaging for a Print. You can read more about packaging prints
here.Tip: For some reason, prints are exported in game
in reverse alphabetical order. This means if you name all of your prints in order starting with 1, 2, 3, and 4, they will export in game as 4, 3, 2, 1. So it is helpful to name all of your prints starting with a number, counting backwards, so that they all show up in order in game and are easy to place.
Then once you have properly packaged the decals and
installed them, just lay out your print bricks and print each individual print in order!

I hope this tutorial was helpful! If you have any questions or parts were confusing for you, just ask!