Frequency:
Fiber lasers work by emitting light in fixed intervals. By increasing the frequency the intervals are
shortened. This causes the laser to be fired with greater power and subsequently makes darker engraving.
However, if the frequency is too high certain material can potentially catch fire. However, for stainless steel we
have to worry about a different effect.
By increasing the frequency of the laser machine the stainless steel will be heated up fairly quickly.
This can affect the color engraving process. If the material is too hot it will not engrave in color. There is an on
the off chance that it will engrave in color however the color will look different once the material cools down.
Hatching and Line Spacing:
Hatching types, or infills as we like to call them, is the pattern in which your engraving is done. As
mentioned before
Bi-directional or Optimization Two-Way hatching are used for color engraving
. The way the
pattern is engraved depends on the line spacing. The larger the spacing the less the object is filled in. Since
we’re trying to engrave colors we want to have a small infill. The ideal spacing for colored engraving is
.001-.005. It’s important to keep in mind that simply by changing the line spacing the colors can be different.
Focus Distance:
Fiber and MOPA lasers work by emitting two beams of light that will burn the material when they
converge. For that reason these laser systems must be in focus to engrave. The focus distance is within a few
millimeters, meaning if you switched from a 1mm stainless steel sample to a 2mm sample your material will
still engrave without having to refocus.
This become important in color engraving because it means you can raise and lower your laser head
to help get different coloring. Let's say you get a blue marking but your aiming for purple, you can try lowering
the stage to get a hotter etch and could end up with a shade closer to purple.
Levelness:
You should always make sure your object is level to ensure proper engraving. Engraving in color
simply adds another reason as to why to do so. As stated above, raising and lowering the laser head can
change the colors. The same can apply to an unleveled object. One end of the object will have a different
shaping than the other.
Rainbow Engraving:
Rainbow Engravings are engraving that slowly change color as engraved. These types of engraving can
be done in both Fiber and MOPA lasers. These engraving are done in a higher line spacing of .02, a
medium-low to medium speed, and medium to medium-high power, such as 45 to 70%.
Remember that this is just a General Guideline for you to help better understand how
complicated engraving in color is. It’s up to you to find out what method works best for your
needs.
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Section X. Color Engraving
Color Engraving Parameters:
