A thousandth of an inch is equal to one millimeter, which is a unit of measurement that is also referred to as a mil. The increase in the thickness of the tarpaulin that happens as a result of the increased number of IDs is directly proportional to the number of IDs that are used. Tarpaulins typically have a thickness of 6 mils, but customers have the option of ordering them with a thickness that ranges from 3 mils all the way up to 23 mils in the event that they require a canopy that is excepti...