The name fibro is short for "fibrous (or fibre) cement sheet", more commonly called "asbestos cement sheet" or "AC sheet". It is a building material in which asbestos fibres are used to reinforce thin rigid cement sheets. Although fibro was used in a number of countries, it was in Australia where its use was the most widespread. Predominantly manufactured and sold by James Hardie & Co. until the mid-1980s, fibro in all its forms was a very popular building material, largely due to its durability. The reinforcing fibres involved were almost always asbestos.