Impossible Triangle Wood Art

Optical illusions are fun. I especially like impossible objects: a two dimensional drawing of a 3d object that cannot exist as a solid object in real life. Here is my version of the Reutersvärd triangle, created as wood art. I show you how I made it.

Three different colored wooden boards, about 1/8” thick by 2” by 20”. Here I am using walnut, hickory, and cherry.

Three strips of 1/4” thick plywood for the backing, about 10" long

Wood glue

Laser cutter, scroll saw, or band saw

Random orbit sander or finishing sander

Make the wooden boards from three different species, 1/8" by 2" by 20". From each of the wooden boards you will laser-cut (or scrollsaw/bandsaw) the following pieces: five diamonds, one truncated diamond, two angles, and one truncated angle. I have attached the svg files for your use. The sides of the fully assembled impossible triangle are about 10" long. Pay attention to the grain direction, so that the assembled pieces have their grain aligned; it looks better that way.

Optionally, cut the center star.

Finally cut and glue the plywood backer frame to the dimensions shown in the pdf file. It is an equilateral triangle with a 10" side and slightly truncated corners. I choose to make the support frame so it is hidden behind the actual artwork.

Assemble the wood pieces without glue to make sure everything fits together. You may have to do some minor edge trimming or sanding. Once you are satisfied with the fit, glue the wood pieces to the plywood backer frame working your way around the center. Mark the center line of the backer frame to align the pieces.

If you use a solid backer board you can glue in the center star and finish the plywood edges with thin strips of wood.

After the glue dries sand the entire surface smooth, up to 220 grid. Since all of the tiles overhang the backer frame by quite a bit, I cut some plywood pieces to support the art work during sanding. Finally, I used tung oil for the finish.

If you don't have access to a laser cutter, or if you want to try a different approach, here are some alternative options:

1. Use a scroll saw or band saw to cut the pieces
2. Use veneer for the wood pieces and cut with a sharp knife
3. 3d print the pieces in different colors; assemble or use as tiles for a puzzle. Attached are the stl files for 3d printing, 3mm thick. If you do this please share with the Instructables community.

Here is a design I made some time ago and published on Instructables.

And here are some other impossible object designs that I modeled in Fusion 360.

1. Impossible Cube
2. Impossible Square Links
3. Penrose Triangle
4. Impossible Trident