Nital

Nital is a solution of alcohol and nitric acid commonly used for routine etching of metals. It is especially suitable for revealing the microstructure of carbon steels. The alcohol can be methanol, ethanol or methylated spirits.

Mixtures of ethanol and nitric acid are potentially explosive. This commonly occurs by gas evolution, although ethyl nitrate can also be formed. Methanol is not liable to explosion but it is toxic.