The Portland Guitar Practical Intonation System allows for easy adjustments of guitar nut and guitar bridge-saddle fixing intonation errors and returning a purer tone.
For comparison the following two basic examples of common string tuning systems and their inherent flaws are presented.
Tuning pegs would be considered a first order tuner. The tension is changed to make each string play the desired open note. When a closed note is played it tends towards sharp. This is an intonation error and thus the need for compensation.
Your standard intonation-compensation system is a second order tuner, allowing some control of the scale length and fret position to remedy the tendency to sharpness. Modern methods revolve around shaping the nut and saddle to affect the scale length and starting point of each fret. These are insufficient, and permanent.
The Portland Guitar solution allows for precise changes by splitting the saddle and nut into six pieces, two for each string at the neck and bridge. A set of well-hidden miniature brackets, fittings and set screws allow the precise and repeatable placement of each nut-saddle in the nut-saddle bracket. Just the right intonation compensation can be applied to each string independently to ensure the purest sound possible every time, regardless of age or humidity.