Thank you for contacting us with your inquiry.
It is possible to engrave in a cavity with some programming modifications, but the crispness attained by engraving through the anodized layer (which is quite hard) is lost, so the results will not be comparable to the same engravings cut through the anodized surface.
One alternative to get around this would be to engrave the cavity a little deeper, then have an anodized panel milled to drop into the cavity.
For a small fee, we have also created custom HPGL's that mill a cavity around the shapes of the desired text, resulting in an embossed look. This restricts your letter color to the color of the panel, but the finished look is outstanding.
If we can provide any additional assistance, please do not hesitate to let us know.
Customer Service Manager