Nylon is the most common material for construction of carpets. Both nylon 6 and nylon 6-6 are used. Nylon can be dyed topically or dyed in a molten state ( Solution dying). Nylon can be printed easily and has excellent wear characteristics. In carpets, fibre nylon tends to stain easily because it possesses dye sites on fiber. These dye sites need to be filled in order to give nylon any type of stain resistance. As nylon is petroleum based it varies in price with the price of oil.