Begin by punching out squares from each of the swatches, careful to keep the swatch colors together from each. You can also cut the squares by hand with a cutting board if you desire.
Once you have all your square sets punched out, count them (important!) and organize them how you would like to see them out on the foam core.
The size of your art is dependent on how many swatches you "acquire" and the size of your squares. I had around 335 squares at 1" in size. With a little math, my final size was calculated at 16"x20".
My foam core was 20"x30" which was too big for the number of squares I had. So I marked off guidelines where the cut off edges would be but I did not precut the board to size. You'll see why shorty...
Next begin gluing down your squares on you first row.
Align them edge to edge as straight as possible, especially for your first row. You may even want to draw a guideline to help keep things straight if you are having trouble (like me).
As I finished my first row of 16 squares you can see that they did not fall right on the 16" guideline I had made earlier. I assume this is due to tiny gaps between squares as they are set.
Note: I had tried this project before w/ squares that were hand cut and had the same offset issue. Plus I found hand cut squares were always a little off and hard to make straight, hence the punch.
Once you finish your first row begin again with row 2, aligning the squares to each other.
Continue on with row after row in the same fashion.
Here is the board with all the swatches laid out. FYI: You can see there is a little overhang on the bottom due to the gap issue I mentioned before.
To cut the board to size, take a sharp edge knife or razor and carefully cut just beneath the last line of squares. Avoid cutting the squares as you go.
Snap the first cut line you did to break the foam between. Then finish by cutting the back part in the foam core board to sever the excess.
Then you have your final artwork which to can hang as is with some wall adhesive or....
...you can stick it in frame! Voila!