The detail that caught me off guard is that these koozies were made entirely by hand for the last couple of months, and only now has the maker moved the cutting and engraving over to a machine. That backstory makes the finished pieces look even better, since the design clearly came from a lot of practice with the form.
The workflow is a nice blend of old and new. A hand-drawn paper template gets scanned on an HP scanner, then the vector geometry is cleaned up in Affinity Designer with the pen tool. From there LightBurn generates the cut paths, the stitching holes, and a raster-engraved logo. The leather stock is masked with low-tack paper tape before it goes into an enclosed Creality Falcon2 Pro 22W diode laser, which is fitted with an overhead camera, a ventilation fan, and an air assist compressor.
Plenty stands out in the construction. The contours and a Kumiko-inspired fretwork pattern are set to line cutting, while the logo gets a fill engrave. The seam is closed with white thread in a corset stitch pattern using two needles, which must be slow work even with the holes pre-pierced. The base and sleeve are joined with brass tubular rivets and washers, set with a hollow rivet setter and a rawhide mallet on a small bench anvil, then trimmed with pliers and peened. Retention tabs on both the sleeve and the separate round coaster base get their mounting holes from punch pliers, and leftover cutout waste is picked out after the masking comes off.
The one trade-off I see is that the laser only handles part of the job. The seam is still sewn by hand, so each piece keeps a manual step. The finished koozies fit around rocks glasses for thermal insulation, with the coaster integrated into the bottom.
Project by Ethan Carter Designs. Watch it on their YouTube channel: