The chiral nematic phase exhibits chirality (handedness). Cholesteric liquid crystals are also known as "chiral nematic liquid crystals". Such mesophases include isotropic, anisotropic, nematic and cholesteric. Chiral discotic phases, similar to the chiral nematic phase, are also known. Conic phases, except nonpolar nematic, are polar phases. Twisted-nematic or super-twisted nematic mixtures often contain a small amount of such dopants. Longer acenes align better in the nematic liquid crystal phase. Twisted nematic (TN) displays with 6-bit color depth per primary color have lowest quality. This issue arose due to the use of 6-bit per pixel Twisted nematic LCD screens. Methods used include the Freedericksz transition and the twisted nematic field effect. One of the most common LC phases is the nematic. Each of the three terms represent a type of distortion of a nematic. FSTN (Film Super-twisted nematic) can improve image sharpness. The word "nematic" comes from the Greek (""), which means "thread".