These are semitransparent sheets and are of following types: Tracing Sheet available in 90/95gsm, 110/115gsm and 150gsm. It is used by artist and printers to develop tracings for screen printing.
LPF film is of 100 microns and is available in A/4, A/3 and 12×18 Size.
They are available in A/4 size and are used for making ID cards for corporates and schools.
It is used in OHP projector as well as in spiral binding available in 100 and 175 micron.