These medium strength high density garbage bags are 12 microns thick. In our humble opinions, High Density Polyethylene (nickname: HDPE) is pretty amazing stuff. To give you some perspective, a micron is a millionth of a meter: one human hair is 40 to 50 microns wide. So these wonderfully lightweight bags are amazingly thin, but still remarkably strong, able to carry loads of up to 50 lbs! This means they handle wet trash with aplomb, so you’ll often find these waste basket liners in bathrooms.