This was a fun little project I came up with after going to Home Depot and literally take a swatch of every color (the people there could care less). I couldn't come up with a good design really that would showcase all of the colors well, so I stacked them, kind of. Since the paint swatches were free, this is a project that really doesn't cost anything. I used swatches that were solid squares, but it could be done with anything. After I glued it all together, I sprayed it with an acrylic sealant.
First, get however many paint swatches you want to use. I used 14 swatches per coaster and I made 4 coasters. That's 56 total swatches.
Lay them out in the order you will glue them down in. I did in rainbow order type of thing.
To make the first coaster (if you are doing the design I am) start with the coaster you want on top. Orient it how you want, then grab the hot glue gun and glue the second swatch underneath so it sticks out just a bit.
Now just keep gluing swatches underneath. You could probably start with the bottom swatch and glue up but I am weird and did it top to bottom.
Finish the gluing. If you would like more coasters, repeat the steps.
Now spray them with a sealant (outside!). Let dry.
Set out and enjoy!