Lilac paper keyboard

What you'll need

• Print the eight color OR eight coloring sheets at 100%. Check the 50 mm line. Use 160–200 gsm card for the case and caps; start with the same card for the springs. Also prepare thin cereal-box card, scissors, glue and clear tape.

Assembly overview

1. Print and prepare. Print the eight color OR eight coloring sheets at 100%. Check the 50 mm line. Use 160–200 gsm card for the case and caps; start with the same card for the springs. Also prepare thin cereal-box card, scissors, glue and clear tape.
2. Fold a practice keycap. Start with T on sheet 6. Fold its four 7 mm sides down. Apply glue to the four small corner tabs and stick them INSIDE the neighboring side walls. Keep the underside open. Fold the printed face outward.
3. Make one crossed paper spring. Use S59 and S60 for practice. Glue their first 8 mm squares together at a right angle. Fold the lower strip over the shared square, then fold the other strip over it. Alternate until the strips are used up; glue the last squares together. Keep glue off all moving folds.
4. Mount and test the practice key. Glue one spring end to the underside of T, centered. Glue the other end to TEST BASE. Gently open the folds to aim for a 10 mm resting height to the underside of the key face, leaving 3 mm below the skirt. Press and release 10 times. If it stays down, remake the spring with different card before making the other keys. Sound and spring life depend on the paper.
5. Assemble and reinforce the case. Fold A at its four long edge lines. Glue the four corner tabs inside the adjacent walls. Trace B onto thin cereal-box card and attach it behind B. Tape the four lower edges of A to B, making a stiff, closed 230 × 86 × 10 mm base. Keep the spring positions visible on top.
6. Fold the 28 keycaps. Make K1–K27 like the practice cap, leaving the bottoms open. Make the longer K28 in the same way. Keep each printed letter upright and use the layout shown. All caps use the same 7 mm skirt depth.
7. Make and mount 27 springs. Pair S1+S2, S3+S4, and so on through S53+S54. Fold each pair like the practice spring. Glue one end to its matching white square on A and the other to the center underside of K1–K27. Keep the skirt clear of the base and neighbors; glue only the spring end faces.
8. Support the long space bar. Use S55+S56 and S57+S58 for two springs. Place their centers 42 mm apart under K28, 9 mm from each end of the key face. Glue the lower ends to the two K28 positions on A. Set both springs to the same resting height so SPACE stays level.
9. Check every key. After the glue dries, press and release each key gently. Check that the cap does not rub its neighbors or remain pressed down. Replace a flattened spring instead of forcing it. Paper springs provide an experimental press action; a crisp click is not guaranteed.
10. Finish your lilac keyboard. Check the three rows: QWERTYUIOP / ASDFGHJKL + DEL / ZXCVBNM + SPACE. Keep the keyboard dry and press near each key center. This is a paper play keyboard; it does not connect to a computer.