Looking after landing nets.
Modern carp landing net meshes are generally manufactured from materials that resist rotting; usually soft nylon/polyester based, unlike early cotton-like materials which were prone to rotting, especially when not washed out after use.
However the seams on cheaper meshes may be stitched with cotton and not nylon/polyester, but even then would take a while to rot.
One of the most common reasons for holes appearing in net meshes is rodent attack. If a net is left lying on the ground then it won’t be long before rats finds it, especially if it smells fishy. Always lean your net against a bush or tree branches where the rodent problem is least likely to occur and wash it out in the lake or river after every fish capture. This will reduce the chances of the net becoming a target.
Another way of reducing mesh damage is to clip the bottom of the net to the handle when landing a fish, this will reduce the chances of the mesh getting snagged in lakeside vegetation which can cause the mesh to rip when lifting your catch from the water.