I didn't take separate pictures of each item I used to build the lightbox, but I'll list everything out below.

Yellow sticker reads: "Bad planning on your part does not constitute an automatic emergency on my part."

The most important piece is the case.  It's what you'll see most, so it should look nice and you should be extra careful not to damage the exterior during construction.  If you're handy enough, you can certainly build one yourself.  I don't have a woodshop, so I bought a 12"x15" shadowbox from my local hobby store.  Whatever you choose, be sure it puts several inches of distance between the glass and the back of the box.  If the LEDs are too close the acrylic, their light won't be diffused enough.

Second most important is the patterned acrylic itself.  I like the effect created by the diamond pattern, but don't let that stop you from finding something different!  I purchased mine from acrylite-shop.com because they laser cut it to the exact size needed.  (As of this writing, they appear to offer a transparent honeycomb pattern that they didn't have before.  It would probably look very nice.)

Here you can see a few of the different patterns side-by-side.  The big sheet at the bottom is the one I actually used.  (Notice how the diamonds are quite a bit bigger in the bottom right compared to the top left?  That's because the bottom right corner is about 0.3" further away from the LEDs than the top left.)  Along the top row, left to right, the small samples are diamond patterned, honeycomb patterned and "stippled".  (The small diamond and honeycomb samples also had an iridescent coating that doesn't show up in this photo; acrylite-shop.com calls it "Radiant").  It only looks good in white light; I wouldn't suggest it for this project.)

Full parts list:

• shadowbox
• patterned acrylic panel
• Arduino Uno
• 12mm Diffused Flat RGB LED Pixels (strand of 25)
• 5V 2A switching power supply
• 2.1mm female DC power jack
• posterboard or foamboard (black)
• razor knife
• wire cutters
• heat shrink tubing OR electrical tape
• yardstick OR meterstick (depending on where you live)
• pencil
• hot glue gun or epoxy
• wire
• drill with 0.5" and 0.25" bits
• small phillips screwdriver
• calculator and notepad
• computer and USB cable

Pictured but not used:

• hammer (if frustration levels rise too high)