What do I need to consider when laser engraving metal tumblers?
Thermal tumblers are popular lately. Personalized, they make great gifts, especially at work. You can use a laser-turning device for round items, or a holding device or jig. With a turning device (or rotary device), you can cover a larger area with your engraving. Without a turning device, you might make up for the smaller area you can engrave by offering to engrave two sides. The holding jig you use can be as simple as two triangular cut blocks of wood glued to a board side-by-side to prevent the tumbler from rolling.
Laser settings vary based on whether the aluminum or stainless steel is coated with a paint, anodized, or powder coated. I do not laser powder-coated metal as I find the coating extremely difficult to remove and not worth the effort. I love anodized tumblers as the lasering is crisp, clean, and fairly easy to remove. Uncoated aluminum tumblers can be personalized with a chemical such as CerMark. To provide a clean mark, I use SD-20 All Purpose Degreaser from JDS Industries to remove the colored haze from the lasered area.