We begun by creating a poster using simple form and Counter form techniques (black and white space) using Adobe Illustrator
Begin by drawing a rectangle leaving a margin around the edges.
Then Split into grid for this I used 6 x 6
I used Gil Sans 250 pt to type large letters
Select all the letters and Send them to the Back
Move a letter over the first box, select both and create a clipping mask.
You can move the letter freely using the Direct Selection Tool.
Repeat the previous steps
Some Variations