Edward Varnish and Frederick Hale Thomson patented the technique for silvering glass vessels in 1849. This is a hazard in some formulations of chemically silvering mirrors. It is also used to clean glass before silvering when making silver mirrors. The silvering is achieved with reflective fish scales that function as small mirrors. Most fish in the upper ocean such as sardine and herring are camouflaged by silvering. Most fish in the upper ocean are camouflaged by silvering. Silvering was put on the mirror chemically, typically by the mirror maker or user. It has also been used in the process of silvering mirrors. The hair around the eyes and muzzle may also show signs of silvering. The company was purchased and renamed Plate Glass Bevelling and Silvering in 1899. It is one of the dominant types of aquatic camouflage, along with transparency and silvering. The "silvering" on precision optical instruments such as telescopes is usually aluminum. The process for creating the silvering was developed by Steinheil's friend Justus Liebig. Other methods including transparency and silvering are widely used by marine animals. A transparency effect can be achieved by silvering to make an animal's body highly reflective.