Try home building supply store, i.e. Lowe's Home Depot etc.
it is used by furtilindation substances i guess
Corrugated Plastic
A "mil" is a "military unit" and equals 1/1000 inch.So 8 mils = 8 thousandths, or 8/1000 in or .008"
plastics are used in many acations. for rulers and sharpeners and lots more things. (: (;