Review on 📚 Wire Shelf Liner Set of 4 - Graphite, 14x36 Inch, Ideal for Shelf Organization by Brian Hrdlicka

As far as I can tell "strength" is not a universal measurement but has different meanings depending on the material. 30 gauge sheet metal will be about 0.3mm. For plastic sheeting (such as garbage bags), size 30 would be 7.6 microns (thousandths of a millimeter). I could not find a standard for polypropylene sheets. So I had no idea what the advertised thickness of "30 gauge polypropylene" would actually be. In the photo, the reflection at the edge of the sheet made it about 1/16 inch (about 1.5mm) tall. We have acrylic sheets for wire shelves which are much thicker but they were expensive so I figured around 1.5mm would be a reasonable expectation for flexible shelf liners. They are actually 0.65mm or 1/32 inch thick. Thicker than 30 gauge metal but thinner than I expected. They cannot support weight at the edges and flex a little between the wires of the shelves. On the other hand, they are cut to the right dimensions. They act as inserts for gratings and prevent small parts from falling. But they're not quite what I expected for the price.