Engraving on Glass

Is there any set DPI, Speed and Power for engraving on glass. When I look at the mason jars, it is 300 DPI, 100 and 100. The ornament ZCTO01 is 600 DPI, 100 power and 50 speed. I am looking for really clean, crisp edges on the engraving. Can I go higher than 600 DPI? Will 1200 DPI make a difference?

We are attempting to engrave on champagne flutes and need it to look crisp.

Thanks