To kickstart our series of short articles featuring creative materials to work with using your laser cutter, let's take a look at leather! We'll show the process of making labels with automated stichlines using LightBurn.
What is leather?
A versatile material, just as your laser cutter is a versatile tool for countless creative projects. It is not like fabric, plastics or wood however, so there is a couple of things to keep in mind when working with leather.
Leather scorches and bends if exposed to too much burning! On the picture above, you can see the first cutting attempt done with two passes using the same settings. With correct configuration, a single pass is enough to cleanly cut leather. As leather is a natural material that comes from animals (we will not include "vegan" leather in this particular article), the thickness, quality, fibre density will vary, and you have to account for that. Always do some tests at the edges to see what works and what would ruin your material!
Charring is normal; you are burning into what's essentially skin with fat, oils. To wipe off the soot, just plain wet cloth will suffice. Do not leave it wet for too long as that will warp the leather - however, if you want to emboss your material, or warp it on purpose, this technique is good to keep in mind.
Leather has different texture on each sides: the flesh side, and the skin side. The skin side is the "smooth" surface, the flesh side is the "furry" or "hairy" one. You can engrave on both sides, but depending on your project, it makes a huge difference which side you engrave into. The flesh side will always be less accurate in details than the skin side, since the fibres will shift around from touching. If you engrave deep enough, wetting the surface then using a press would compress the fibre and your design will be more visible and clearer.
Adding automated stitches along a path/outline
To make evenly spaced stitches in LightBurn, you have to open the layer settings (double click on the layer you want the stitches to be on).
This layer needs to have an outline, and must be set to "Line" mode, not "Fill". As with the cutline, you can perform this with a single pass, adding a second pass is optional.
"Perforation Mode" lets you select the length of the stitches as well as the spacing between stitches. The output will show in the preview window, and not on the design itself!
Here are the finished labels after wiping off the soot. As with the edges, the stitches will also be charred: use a wet cloth or cotton buds to get out as much soot as possible. Sewing with light coloured threads may still become subjects to discolouration.
Safety precautions and warnings
Keep in mind that leather will smell quite strong when it burns (imagine burnt hair, just much worse), and you should pay extra attention to the material while it is being processed by the laser. Since leather may bend or warp along the laser beam, if it gets in the path too often, there is a chance the piece may be ruined or catch on fire. Good ventillation is crucial, as well as making sure that all the smoke is cleared out of the machine before opening the lid. The smell can stay on clothes and hair for a while! It is adviced to wipe off your machine interior (rails, etc.) after processing leather, using dry cloth, rubbing alcohol or the combination of both is advised.