This birthday card is made out of four layers. Once put together, it is a zig-zag fold. You can use different colors for each layer or in the example, I used two colors of 8.5 x 11 card-stock in alternating colors to make the card.
The black outlines cut while the red lines score the folds for the hinges.
view from the top of the card showing the hinged layers
[SGV file]