Business-card cube

This device cannot show the 3D view. Follow the step pictures and text below instead.

1. 

   1. Cross two cards

   Lay the red card sideways, white side up. Turn the blue card upright, coloured side up, and lay it across the middle of the red one. The white sides touch, and the overlap is a square.

2. 

   2. Fold the bottom card’s ends

   Fold the right end of the red card up over the edge of the blue card and press it flat. Fold the left end the same way.

3. 

   3. Turn over

   Turn the pair over as it is. Now the blue card is underneath.

4. 

   4. Fold the other card’s ends

   Fold the top end of the blue card up over the edge of the red card and press it flat. Fold the bottom end the same way.

5. 

   5. Open the flaps and pull apart

   Open every folded end back to a right angle. Lift the red card off and set it down the other way up. Each card is now a unit: a square with a flap standing up on two opposite sides.

6. 

   6. Fold two more pairs

   Make two more pairs the same way from the last four cards. Lay the yellow and blue cards sideways, white side up, and lay the red and yellow cards upright across them, coloured side up. Fold the ends of each bottom card up over the edges of the top card.

7. 

   7. Turn over and fold the other cards

   Turn both pairs over as they are. The red and yellow cards are now underneath: fold their top and bottom ends up over the edges of the cards lying on them.

8. 

   8. Open the flaps and pull apart

   As with the first pair, open every folded end to a right angle. Lift off the yellow and blue cards on top and set them down the other way up. All six units are ready.

9. 

   9. Set down the floor

   Put one red unit in the middle with its flaps standing up. This is the floor of the cube.

10. 

    10. Stand up the blue walls

    Stand the two blue units up with their flaps pointing inward and lower them inside the red flaps. The red flaps hug the blue walls from outside.

11. 

    11. Slide in the yellow walls

    Pick up the two yellow units and open the flap that will go at the bottom out flat. Stand the units up, lower them inside the blue flaps, then fold the opened flaps in under the floor.

12. 

    12. Close the lid

    Open the two top flaps of the yellow walls straight up. Turn the last red unit flaps down and lower it on top, its flaps going down outside the blue walls. Fold the yellow flaps back down over the lid. The cube is done!

13. 

    13. Turn it and look

    Turn the cube around. Opposite faces have the same colour, and on every face two flaps of another colour wrap it from outside. It holds together without glue.