Letter (paper size) "official" "Government Letter" size, , was used in government, while paper was standard in most other offices. In the U.S., paper density is usually measured in "pounds per ream" (of 500 sheets). Typical Letter paper has a basis weight of paper of – the weight of 500 sheets (a ream) of paper at and at 50% humidity. One ream of 20-pound Letter-sized paper weighs , and a single Letter-sized sheet of 20-pound paper weighs , which is equivalent to 75.19 g/m. Some metric information is typically included on American ream packaging. For example, 20-pound paper is also labeled as 75
Paper drilling drill is used as well for paper drilling machines as for the tools used for paper drilling. Paper drilling is a method to drill round holes into paper and other materials. For this purpose hollow paper drill bits are clamped into a driven spindle which drills into the pile of paper. Paper drill bits are available for different hole sizes and in different coating qualities. Unlike hole punching, where only one or a few sheets may be processed, a large number of sheets can be processed with a paper drilling machine. Depending on the type of paper drill either the