Laser Mark Multiple Passes to Minimize Damage
Multiple passes may result in a better marking for almost everything from mugs to powder-coated metals.
As a laser engraver, you are going to run into unique products with unique challenges. Using multiple passes helps minimize any damage to the product. If you find yourself requiring multiple passes to obtain a satisfactory laser mark, your power settings are usually too low. But in some cases, simply increasing the laser power is not always the solution. You could distort, melt, or even set the piece on fire.
In my experience, using a lower power combined with multiple passes can often result in a better marking. The benefits of a second pass can be echoed when laser marking coated metals and plastics, which are sometimes not intended for laser engraving. As usual, you need to be cognizant of any harmful fumes or residues that could occur if laser engraving unknown products. This is yet another reason to have adequate ventilation for your lasers. Over the years, we have used the multiple-pass technique on a wide variety of products and materials. These include everything from binoculars and cameras to mugs and powder-coated metals.
-Richard Korbyl, Columbia Awards