How to prevent micro fracturing of glass

Question- I am marking glass with LMC products and get micro-fracturing. How can I prevent this from happening?

Answer-  Micro-fracturing occurs when the glass substrate is heated beyond its melting temperature and then rapidly cooled to room temperatures. These strong variations in temperature lead to local expansion and contraction and subsequently to micro-fracturing. There are two mechanisms of heating glass substrates: through conduction (ink heating the glass through thermal conduction), and through direct absorption. The latter is present mostly in CO2 lasers due to the absorption at CO2 lasers’ wavelength of operation. Consequently, solid-state lasers generate smoother marks. In both cases the micro-fracturing can often be minimized by lowering the power and the speed, thus creating gentle conditions for bonding – heating the ink just enough to bond to the surface and scanning slowly enough to deposit enough heat to bond.