How to Design an Impossible Puzzle

My mum puzzles a lot. Most puzzles she does are 1000 pieces and a lot of work but not very hard to do. There is a system in laying these puzzles. You start with the corners and the edges, then sort the colors and divide the puzzles in parts, like the sky, the bricks, the grass etc.

So to make an impossible puzzle, I wanted to mess with all these ideas.

First I make it only a couple of pieces.

There will be no image.

And those corners...

You will need

• Lasercutter
• Acrylic
• Glue

I design in Gravit Designer, but AI, Corel or Inkscape will work as well.

For this project I took my drawing tablet from under the dust, but a mouse or trackpad will work fine.

Look at the pictures for the instructions.

• Set the grid at the average size you want your puzzle pieces to guide you.
• The first step is the outer border of the puzzle. This is also the first trick. I've made the 'square' nog fully square, and it is also not exactly straight, so the puzzle will only fit in one way.
• Finally I slightly curved two edges to make it even harder to fit the puzzle in.

I design the puzzle first in black for easy designing and only change it to thin red lines for the laser when I am finished.

• An experienced puzzler will start with the corners, so I will add a fifth corner somewhere in the middle of the puzzle.
• The next pieces that a puzzler will go for are the edge pieces, so I make sure dat some of the edge pieces look like they belong in the middle.
• To make it even harder I will also copy some sides of pieces so they will fit to the wrong pieces as well as the right piece.

When the whole puzzle is designed, I change the lines in the red thin cutting lines for the laser.

• Zoom in to see the details.
• Make the teeth of the pieces smooth. (don't change the copied pieces or they won't fit to each other anymore)
• Make sure that all lines connect.
• I also added tekst that didn't line up, to make it even harder to solve the puzzle.

Because to me the fun is in the designing, I didn't include the designs this time, to challenge you to design your own. (OK, after a request from Bill, I did add the design after all)

• Before going to the laser, I taped both sides of the acrylic to get a clean cut.
• To retrieve all the small pieces easily from the laser cutter, I put some packing tape on top, so the pieces can't fall in the crumble tray.
• Also cut from an other color of acrylic, just the outer dimensions for the under layer of the puzzle.

By far the most work is the removal of the tape. (if someone has a really good method for it, please let me know)

• Glue the outer border on the under layer. Make sure to have both pieces the right way, because the square isn't square, remember?!
• Put something heavy on top to let it dry.

I've also made a box for it and wanted to show it to you, just to show off.

It took some very bright kids 10 minutes to finish the easy, 26 piece puzzle. It took my mum more than half an hour.

We haven't tried the 29 pieces hard one yet, but we will be soon.

I've found out that I am not the first one to design a puzzle like this so if you want to buy one and you are not from the Netherlands you must be able to find it somewhere.