I often engrave these 2 inch thick boxes on my chinese laser with no issue. One of the reasons i bought the GF is because of the ability to quickly sight and lay out designs using the camera. What i am finding though is if i use the camera to line things up its often off as much as 5mm in the direction of the cameras parallax being such a wide angle lens. Just wondering what people are doing to compensate for this. here is an image showing what i am talking about.