• Gibson has a long history of making guitars, such as the Les Paul Gibson hollow body, the Gibson SG and the Flying V guitar. One of the secrets to Gibson's success has been the use of proprietary technology, such as their PAF (Patent Applied For) humbucking pickup. This was the first humbucker and was invented by Seth Lover for Gibson in 1955. Since then, the PAF pickups were placed in several guitars until the mid 1960s when the patent was approved.
  
  

Casing

• The most visible part of the PAF humbucker is the casing. For the PAF this can be either square or pill shaped with rounded edges. The casing style and material tells a great deal about the humbucker and the guitar's age. The earliest PAF humbuckers were brushed stainless steel with stainless steel screws and were featured in guitars such as the Gibson Les Paul Standard. By 1959, the pickups had changed from steel to nickel plated brass with similar screws and an optional customization of gold plating which would be applied over the nickel plating. 1958 saw the beginning of plastic cased Zebra PAFs on guitars such as the Les Paul Gibson standard and the Flying V.
  
  

Magnets

• Magnetism is very important to any pickup and the types and configurations of magnets used determine the shape of the sound being produced by the guitar. Gibson used Alnico magnets, but for earlier PAF pickups, those magnets could be of several different sizes and strengths. This is because Gibson used magnets made of aluminum, nickel or cobalt of several different grades without any particular consistency. This produced a high degree of sound inconsistency and different units of the same model guitar could sound dissimilar when plugged in and played. By 1961, Gibson began using Alnico size 5 magnets which made the sound uniform for PAF pickups.
  
  

Wiring

• Also integral to the sound of the guitar is the type of wiring used. The PAF guitars use a plain enamel copper wiring with a slightly purple hue in their inner workings. Later the wire coating would switch to a polyurethane coated wire which had a reddish tint. The coating and wire distribution change the amount of electrical resistance and can change the sound signature of the guitar. All genuine PAF humbucker guitars have a sound pickup rating of between 7.5 and 9.0 K Ohms.