Which type of varnish is used for fabricated iron and steel items in buildings ? 

Explanation:

Asphalt Varnish:

• Asphalt varnish is a bitumen-based product that provides good resistance to water and corrosive environments because of its oil base which makes it durable.
• It has been traditionally used for coating iron and steel structures and provides a glossy finish that is also aesthetically pleasing.

Spirit Varnish:

• Spirit varnishes are a solution of resins in an alcohol solvent, and they dry quickly because of the swift evaporation of the alcohol. 

Water Varnish:

• Water varnishes are modern, eco-friendly alternatives made by emulsifying a polymer as resin. They're safe to use and clean up easily with water.

Spar Varnish:

• Spar varnish, also known as marine varnish, is made with a base of natural oil such as tung or linseed oil mixed with resin. They are often used for outdoor wood applications due to their ability to expand and contract with changing temperature and humidity conditions without cracking.