Absolute black granite settings

[Abdul Baseer Hai]

Hi All

I am trying to engrave a photograph on absolute black granite but am getting a spotty frosty white.
i have repeatedly tried different power combinations without success.
I have a 50 watt Explorer.
Any help with the proper settings will be appreciated.

I have tried engraving on black marble and the results are ok.

abdul

[Lee DeRaud]

I've been using 25% power, 100% speed on a 25W ULS.

Sounds like you're using too much power. For granite, too much power is worse than too little: keep cutting power and/or raising speed until it just barely marks and work back up from there.

[Frank Corker]

I agree with Lee, sounds like too much power. I actually keep a piece of granite to one side that I messed up on (with the negative/positive error) and I run a cropped picture run on that first. It's suprising just how little the power needs to be to get a good result

[Joe Pelonio]

I'll agree with Lee and Frank. OK to use more power and go deeper on clipart and text bu for photos less is best. I wonder how hard it is to "re-polish" granite so when messing up it doesn't go to waste.

[Lee DeRaud]

I wonder how hard it is to "re-polish" granite so when messing up it doesn't go to waste.I suspect that's way more trouble than it's worth, especially if you use your mistakes as "calibration jigs" like Frank said. And the cheapo ($75 IIRC) tile cutter cuts down on the wastage quite a bit as well.

(Note: I'm just engraving the $6/sqft tiles from Home Depot. Someone in the monument business may see it differently...then again, they've probably already got the specialized polishing gear on hand.)