About
Fluorocarbon Lines are fishing lines extruded in a single strand similar to nylon monofilament, except made from PVDF. Fluorocarbon Lines are tough, sensitive and resistant to abrasion.
― In-game description
This is the Fluorocarbon 1 kg fishing line in COTW The Angler.
Its test weight is what the scoring system charges you for. A catch is worth 1300 points per kilogram of fish and costs 300 points per kilogram of line rating, so the same fish scores higher on lighter line. Land one heavier than the line is rated for and that charge comes back multiplied, which is where the biggest scores come from.