How to Make a Laser Cut Plywood Book
Before it closed for renovation, the Fablab in the Martin Luther King, Jr. branch of the Washington, DC Public Library granted free access to a suite of fabrication tools such as 3D printers, 3D scanners, and, everyone’s favorite, a laser cutter. While moonlighting in the lab, I designed and fabricated a laser-cut plywood book. With the exception of the custom, proprietary software I needed to interface with the laser cutter, I only used free, open-source software. Below is a brief overview of the design and build process.
Laser cutters use vector files to chart the path of the laser. Those files use colors to tell the laser whether it should cut through the material or score the surface. The specifications for each cutter are different: some cut on black lines and score on red, and vice versa. The laser at the Fablab cut on red and scored on black. I used Inkscape to design my files, and while it’s a fantastic alternative to Illustrator for day-to-day graphics, its shortcoming in laser-cutting applications is that it is too good. For the purposes of laser-cutting, line width needs to be set to something extremely small, in my case .001px. Inkscape renders this in the viewport with exactness, making it difficult for the human eye to get a global perspective. So I would design my files at 1px and prior to .pdf export, scale all the lines down to .001px width.
The maximum stock size of my laser bed was 12x24” inches. 5x7” is a standard book size, so I created a template of four pages spanning the width of the board.
The content is a combination of hand-drawn crow quill illustrations and vector graphics either created myself or appropriated via search. Images you create on paper and photograph or, for the most part, find online, will be raster and will need to be converted to vector. The process is very easy with Inkscape.
Converting Raster Graphics to Vector
To convert my drawings to vector graphics, I took a photograph and imported the photo into Inkscape. Under Path, select Trace Bitmap. Select the ‘Brightness cutoff’ radio button and adjust the Threshold as needed. I found that most of my drawings converted at .5, but each image will be different.
My crude, hand-drawn graphic, becomes a crude, computer-drawn vector graphic:
I used Blender to create some of the digital assets. For example, before:
For the final export, I overlaid the above images, and spliced them into two pages, like so:
Knowing that I would need to flip my pages to score on both sides, my layout consists of odd pages being scored then cut and even pages getting flipped then scored. Below are a few pics of the process:
Each book took roughly 3 hours to cut. This is due entirely to the detail in the scoring. This time will also vary depending on the laser cutter. You will find the .svgs and .pdfs in the assets directory here: https://github.com/nielsenjared/of-trees-lasers. If you cut your own book using my template or fork my design, do send me pics.