Hello Chris. When it comes to laser markable aluminum the main issue has to do with the type of black color used in the anodizing. For the most part the color is a dye that tints the material as it is being anodized. Since the dye is organic, you will some loss of color over time depending on the amount of exposure. This can be a quite dramatic change in direct sunlight. The key is to use aluminum with an inorganic black pigment. There are two products available with extensive outdoor performance. AlumaMark BlackPLUS for YAG lasers and DuraBlack for CO2 lasers available from Horizons Inc. In Cleveland Ohio. Hope that helps.