Monofilament fishing line is made by melting and mixing polymers and then extruding the molten plastic through a die with tiny holes, forming strands of line, which is then spun into spools of various thicknesses. The extrusion process controls not only the thickness of the line but also the pound test of the line. It is a relatively inexpensive process that results in a less costly fishing line. Because monofilament fishing line can absorb water, caution should be taken when fishing with monofilament in saltwater. Rinsing down your reels spool with freshwater after fishing in the salt will help preserve the line. Unlike Fluorcarbon materials, Monofilament can degrade with exposure to sunlight and degrades over time. Because of this and because of line memory, it is recommended that monofilament line be changed at least once a year. It's important to remember that the cheaper brands of monofilamnent line are not subjected to the standards that the top name brands we carry are.