Miniature conversion refers to the practice of altering the appearance of a miniature or model so as to deviate from the standard version purchased in a boxed set. This practice is quite common amongst hobbyists who play miniature wargames such as Games Workshop's The Lord of the Rings Strategy Battle Game, Warhammer Fantasy Battles and Warhammer 40,000, as well as many of the other games produced by other games and miniature manufacturers. In these circumstances, conversions generally consist of combining parts of different models and modelling putty (such as Milliput or Kneadatite also known as "Green Stuff") to produce a new model with a unique appearance, which is generally a centrepiece of the player's collection, representing a powerful character or monster, or similar.