You start with a pice of drafting mylar that can be found at most art supply stores in letter size sheets. It may also be called tracing mylar. It seems kind of like a frosted overhead transparency sheet.
  • Next cut the sheet down to 3" x 2"
  • Fold the two 45 degree folds as shown and then cut the back edge to the middle of the "X" that is made. When you fold the mylar use a coin or something to make sure you get a very strong crease, it takes bit more to do this with mylar than with paper.
  • Now make the two folds in front for the base and the tall tab that will go between the faces of the NX clamshell. The base should be about 3/8" wide, the tab is whatever is left over. NOTE: these two folds should be made from the opposite face of the paper than the two 45 degree folds were made.
  • Now take glue (I used Elmers) and spread it evenly over the back most triangle. I use a scrap of cardboard to get good even coverage. Now slide the glued triangle behind the one on the closer side and this will form the pyramid. The glue will be workable for a few minutes so slide it around to get good alignment and also press down so glue forms a good bond.
  • Wait 10 or 15 minutes and your read to go.
  • Bonus Step! - if you fold right down the middle of the side of the pyramid that is not doubled up then you can fold this up flat!

    (despite what is shown above fold it outward rather than inward for best stability.)

Although this feels really flimsy it actually locks into shape as some weight is applied and it is very strong. At that same time you can also give this a lot of abuse by deforming it without damaging the product; of course there is a limit to this but its pretty impressive as the video showed. The trick is not to crush it so much that you create new creases in the mylar.