Today’s post is going to be a little different. I am going to walk you through how to create a complex seamless patter in Illustrator. With CS6 on its way, this will be pointless soon (if you end up owning Illustrator CS6) but it may be useful to a lot of people. With this method, you too can be well on your way creating outdated wallpaper. Here we go. I will include screen shots to help out a long the way.

1. Create a new document.
2. Turn on the grid. View-Show Grid.
   
3. Turn on Snap to Grid. View-Snap to Grid.
    
4. Proceed to create 4 squares like this:
   
   Hold SHIFT down to make sure they are perfectly square. Let them snap to the grid. This is important.
5. Copy one of the squares and paste a new one right in the center of those first four. Let snap do the work. It should look like this:
   
6. You will now create the artwork in the square on the top left like this:
   
   Remember that this pattern will be repeated, so pay attention to the parts that hang out of the square, some of these will overlap on the other side.
   
7. Next, you will take all of the art elements (not the squares themselves) and group them together.
   
8. Now you will create some temporary rectangle, shown in pink. Make sure “Snap to grid” is turned on, then draw them on the closest grid point to the edge of your artwork for the left side and the bottom. Now select your artwork group and the left rectangle and click the “Horizontal Align Left” button. The idea here, is we want to be able to duplicate this pattern on the other side and the bottom, so having the artwork snapped to the grid will make it a lot easier to do this. We will now do the same thing for the bottom using the “Vertical Align Bottom” button.
   
9. Now, for your convenience, I have highlighted the grid lines we will focus on for this copy procedure. With snap turned on, we grab the grouped artwork, do COPY, PAST IN PLACE, then hold SHIFT down and drag the new copy to the right, letting the left side snap on that grid we are focusing on. The bottom should already be lined up because we held SHIFT down and drug it across.
   
10. Now we are going to do the same for the bottom squares. Simply select the top two groups, COPY, PAST IN PLACE, then SHIFT drag to the bottom until it snaps onto that lower grid line we are focusing on.
    
11. Now that we have the art laid out, we can delete the outer 4 squares, leaving only the center square. Bring that object to front by selecting it and going Object-Arrange-Bring to Front.
     
12. With the square selected go Object-Path-Divide Objects Below.
    
    This will slice all of the objects beneath it. Now all we need to do is clean it up. Get the Direct Selection Tool (A) and start deleting everything outside that square.
    
    Note: You will have to zoom in very close, go along the edge of that square and select the small parts that don’t get deleted with the broad selections.
13. If you want to, with SNAP turned on, draw a box around your square, send it to the back and you have a background. Now with your artwork selected, go Edit-Define Pattern, and there you go, a perfectly aligned repeating pattern! Eat your heart out CS6!