Trident Custom Coatings is a company out of East Dundee, Illinois that specializes in firearms and some automobile coating jobs, but has recently gotten into customizing Glocks. Specifically the company uses Duracoat, Hydrodipping, Black Oxide, and Nickel Boron for their current coating process.
The company is trying to compete with the likes of Zev Technologies, and Agency Arms when it comes to customizing Glock handguns. This includes such modifications as lightening the slide by a series of cuts, slotting out an RMR placement, stippling the frame, and adding a number of after market accessories such as barrels, triggers, magazine releases, slide releases, and magazine well enlargements. Currently the company has three tiers of product where you can either purchase a Glock from them outright with all the modifications, or you can send yours in to be custom modified according to the tiers of modification.
Their custom coatings are very well done, including the diversity of process of what you want the coating to be, from the choices listed above. From sports team designs to gnarly looking Flying Tiger teeth on CZ 75 Czech Mate competition rigs, Trident Custom does a very good job of getting a complicated design or color scheme onto any type of firearm.