Gudebrod claim their nylon whipping thread is stronger by weight than steel wire - true or not it definitely is high quality whipping nylon. The colour pigment in NCP whipping nylon is preconditioned into a colourfast medium that resists the damaging effects of powerful epoxies and varnishes that break down the colour pigment in regular Nylon thread, thus saving the time consuming steps of applying numerous coats of colour preserver. Rod finish may be applied directly over rod wrappings, however, most experienced rod builders generally agree that at least one sealing coat of colour preserver is required for best results with this thread. This is Gudebrods heavy (D grade) thread which is ideally suited to whippings on heavier rods such as boat rods and rough ground beach rods. Diameter: .305mm Breaking Strain: 5.1lbs Black D Grade NCP - 100 Yard Spool.