First chose the color of acrylic that you want for the puzzle. I chose pink fluorescent that was glossy on both sides. This makes the puzzle harder because the pieces can be oriented from either side. To make the puzzle easier you can chose a piece that has a matte finish on one side.
In the video I used Red on White acrylic sheets. I did the project a second time where I used Carvey and put the fluorescent acrylic in the machine. Each material gives a bit of a different look and feel.
Remember to measure the thickness of your acrylic. The nature of the way cast acrylic is manufactured means the thickness can vary from the actual thickness.