idler roll 9 and is cooled by first and second cooling rolls 10 and 11 adequate heat transfer between the paper web and these cooling rolls can be accomplished by cooling the rolls with ordinary tap water which is typically at temperatures from 58 u00b0 f to 72 u00b0 f most typically 65 u00b0 f the sheet then passes over a large diameter mt hope roll 12 and a large diameter idler roll 13 and is rewound on roll 14 the practical minimum diameter of any of the rolls is about 3 inches the saturator squeeze rolls not shown and the calender steel rolls must be of a diameter and construction that will resist flexing during operation as a practical matter the minimum diameter of any of the rolls is 3 inches temperature of the heated calender rolls line speed and nip pressure are critical in order to achieve uniform caliper and smoothness of the sheet line speed and nip pressure have been found to effect the immediate sheffield smoothness higher speeds and higher pressures equate to lower immediate sheffield smoothness line speed alone effects the sheffield smoothness after 24 hours lower line speeds produced material that had higher 24 hour sheffield smoothness values temperature and pressure have a significant effect on the percent increase in smoothness after 24 hours whereas line speed has only a slight effect higher temperature higher pressure and lower line speeds lead to larger percent increases in smoothness after 24 hours none of the variables were found to effect the machine direction md or cross direction cd miter fold or the cd internal tear line speed was found to effect md internal.