Drying involves using air and/or heat to remove water from the paper sheets; in the earliest days of paper making this was done by hanging the sheets like laundry; in more modern times various forms of heated drying mechanisms are used. On the paper machine the most common is the steam heated can dryer. These can reach temperatures above 200 °F (93 °C) and are used in long sequences of more than 40 cans; where the heat produced by these can easily dry the paper to less than 6% moisture.