This wood rainbow was laser cut from about a half sheet of 1/4" maple plywood; however, the SVG files can be used to laser cut or CNC cut a variety of materials or to cut stickers on a vinyl cutter. Made with 1/4" plywood, this rainbow can stand by itself or it could be hung on a wall if you prefer. I used small tubes of acrylic paint to paint the rainbow, but it could be colored any way you wish (clothing dye, stain, etc.).

Supplies

1/4 inch plywood
Wood glue and/or Cyanoacrylate (CA) glue
Acrylic paint

Step 1: Step 1: Prepare the Design Files

I designed the layers of this rainbow in Autodesk Fusion 360 and exported each layer to SVG format using the Shaper Origin plugin. I then opened the files in Inkscape to combine the paths and adjust the stroke thickness. I won't go into detail about designing the rainbow, but I have provided the final SVG files for each layer for anyone to use.

Step 2: Step 2: Cut Each Layer on the Laser Cutter

Use a laser cutter or other CNC machine to cut each layer at the same scale in 1/4" plywood (or whatever material you have decided to use). When laser cutting, I applied masking to the front of each layer before cutting to reduce some of the charring from the laser cutter. This is somewhat a personal choice and some level of charring is acceptable since the rainbow will ultimately be painted.

I have provided the files for 5 layers, but I found layers 1-4 were enough to provide a cool effect and to make the rainbow be freestanding when cut out of 1/4" plywood.

Step 3: Step 3: Paint Each Layer

Paint each layer in the colors of the rainbow using whatever paint or dye you choose. I used inexpensive acrylic paints that I watered down slightly and liked the result. I painted the first layer (outline layer) in black and then painted the subsequent layers in the appropriate colors of the rainbow. Make sure to notice where the first layer will fall on the layers below when glued together to figure out where the transition between adjacent colors should be so that it is hidden by the first layer.

Step 4: Step 4: Glue the Layers Together

Starting with the first layer, apply wood glue and/or CA glue to the back of the layer and glue it to the next layer, making sure that the outline of each layer is aligned properly. I used wood glue for the majority of the surface area and applied CA glue at a few key points, which made it so that I did not have to clamp each layer for more than a few minutes before gluing the next layers. As you progress past the second layer, if you intend to stand the rainbow up on a surface then make sure that the layers are aligned in such a way that the rainbow will stand. When you have each layer in place you can clamp it with heavy objects or with clamps. Let the glue dry sufficiently and your rainbow is done!