Neoprene

Neoprene traps a layer of tiny gas bubbles inside the rubber, which is what makes it insulate. Because the cells are closed, water cannot flow through the material, so it keeps working when soaked. That is precisely the property you want in cold-weather fishing gloves and cold-water waders.

Thickness is quoted in millimetres. Two to three millimetres suits gloves and shoulder-season use; five millimetres is winter and ice fishing territory.

The cost is heat and bulk. Neoprene waders are far too warm for most of the year, which is why breathable waders replaced them as the default, and neoprene gloves are clumsy for tying knots.

It is also tough. Neoprene resists punctures and abrasion far better than a breathable laminate, so it survives duck hunting and brushy banks where breathables get holed.