Updated: Sep 17, 2022
Attached to every fly fishing vest should be a good net. If we intend on releasing fish the last thing we want is to drag them on shore and manhandle the hook out. Trout have sensitive mouths as well as sensitive immune systems. The less direct handling we have with them improves their chances for a quick recovery from a fight.
A net is no more than a small storage container for a fish, so why does it matter what I use? A couple of main reasons, but it really just comes down to proper care. The slime on a fish isn't there just to make them slippery, it is a mucus membrane just like we have in our noses to ward off bacteria in the water. This is why we always want to wet our hands first before touching a fish. While Bass and sunfish are a little more hardy in this respect, trout are a lot more sensitive. A net that can hold a good moisture level helps keep that slime on.
Secondly, the gauge of the netting matters, as well as the material. Mesh or rubber nets are much better than the metal framed, nylon nets. Fins and gills get caught in the larger gauges of the nylon, and the thin diameter of the netting can put small cuts through the fish's slime membrane, compromising the immune system. Also a properly sized net is important. If you have a 12" net and are catching 18" fish, they just aren't going to fit resulting in more handling. I have two nets that I use here in the Shenandoah Valley. One very fine mesh net for small brooke trout and a larger net with a long handle that allows me to scoop larger trout and smallmouth. This has a looser rubber net that prevents fins from catching.
Nets come in all different styles, lengths, and shapes. This is truly a case of function over form. Find the right net, and then find the frame you'd like to go with it. Remember, keep them wet.