Also known as lead holders, many artists prefer clutch pencils to traditional pencils. The reason is that wooden-cased pencils change their balance and weight over time when sharpened. This can affect some artists in subtle ways. Clutch pencils have a constant weight and balance as well as allowing for different hardness. Although they are more costly initially, they become economical due to the range of refills available. Many clutch pencils have sharpeners built into their tops.