LaserBond lists some suggested laser settings for various substrate materials, but no two lasers are exactly alike, so it takes some experimentation to determine the correct laser parameters in order to obtain the best marking result for any specific substrate material because the chemical reaction can vary between different materials as well as between different alloys of the same material.
Some of the basic parameters that should be considered are (among others, especially if you’re trying to reproduce pictures or images with fine detail):
- Laser power
- Laser speed
- DPI (dots per inch)
- PPI (pulses per inch)
- Laser focus (with a 2-inch lens)
The surface should be cleaned with denatured alcohol or acetone and be free of any dust or contamination. Everyone should also become familiar with the particular laser settings contained within the software being used to control the laser system. Some software uses a percentage of power and speed while others use absolute numbers (i.e. 300 mm/sec = 12 inches/sec) and the actual wattage for the laser tube (30 watts, 50 watts, etc.) as opposed to a percentage. These suggested laser settings can be found on the LaserBond website together with information for converting absolute numbers into a percentage of either laser power or speed.
—Paul Harrison, Laser Bonding Technology