Engraving Quality

As stated earlier, marking diamonds is still more art than science. Like an artist’s pallet, one can control many different parameters of the LMS Cold Laser System to achieve the desired result.

Type of Control Result on Mark Quality
Laser Energy Dots get darker with increased energy
Shot Spacing Lines get darker with decreased spacing
Beam Size Smaller and lighter marks with smaller size settings.
Repeating Mark Mark gets darker, and a little wider
Slow Motion Cleaner characters, better definition
Scaling Make marks bigger and smaller
Font Different fonts have different styles & darkness


Laser energy is the primary way to increase mark darkness. With low energy the mark is nearly transparent. At higher energies the bottom of the mark begins to form carbon deposits. These deposits absorb light and make the mark look dark. Under certain circumstances the carbon can be removed. This can be accomplished by using very strong chemical treatments. Carbon can also often be removed from marks made with low energy setting.

Shot spacing will also change the look of a mark. Small spots with gaps between each spot will produce an effect similar to that of a light, fine pencil.

One can overlap dots to produce a dark, continuous line.

Beam Size will also increase spot darkness, much like power increases, however with a more dramatic increase in spot size.

Below is another example of changes in beam size affecting character quality.

Because the LMS Cold Laser System utilizes a wavelength in the deep UV one can mark over the same place repeatedly without great concern. The software for the LMS Cold Laser System allows the user to repeat the same marks, over the same location, with great precision. By marking the diamond twice, the user can increase the darkness, and size of the mark in a fashion similar to the beam size example shown above. Repeating a mark more than twice does not appreciably increase mark darkness, or width.

Machine rate (marking speed) can be manipulated to change marking quality.