All materials absorb or reflect light energy of a given wavelength. The material’s ability to absorb or reflect determines the effectiveness of that wavelength for marking. Additionally, other factors influence the selection of the wavelength (and laser system): the size of the character to be marked, the desired marking speed, desired line width, the type of mark, the physical properties of the material, the color of the material, the power of the laser, the pulse frequency, etc. These factors interact with each other in a dynamic manner making the selection process very complicated. Based on CLC’s marking experience, the following materials can be marked using the wavelength indicated. However, sample marking should be conducted to make the final selection of a wavelength and laser marker or coder.