For reasons of economy, different thicknesses of PE films – construction sheeting as it is called – is occasionally required. These films are referred to as standard because they are designed to occupy the space of a standard thickness. The variation is termed sub-tolerance (UT) and is given as a percentage. In the following example, “T200 UT20” is a film that has a thickness of 200 my – 20% sub-tolerance = 160 my.
But be aware – many applications specify particular thicknesses.