nylon monofilament fishing line

Monofilament line stretches, which can be bad or good.  Stretch makes line more forgiving when a big fish makes a strong run, but it also makes it harder to set the hook.  The amount of stretch can be controlled by the additives but all monofilament will stretch some.

Lines come in a wide variety of qualities. The more expensive lines have better quality control and will be consistent in strength, color and diameter.  They will hold up longer on the spool and in use. 

The type of chemicals in the mixture can control qualities of the line like limpness, strength, toughness and other desirable casting factors.  The color of the line is also controlled by added chemicals.  Lines can be tailor made to fit a wide range of needs.

A mixture of polymers are heated until fluid and then extruded through tiny holes to form strands of line. The size of the hole controls the diameter of the line as well, to some extent, the pound test of the line. These strands are cooled quickly and would onto spools.

Monofilament fishing line has been around for years and are the most popular kinds of lines. they work for a wide variety of fishing applications and can be made to have specific qualities that help under varying conditions.