PING stamps its sets of irons with color-coded dots that indicate the angle of the golf head relative to the golf shaft, known as the lie angle. The dots are used by golf shop professionals to property fit the irons to golfers of different heights and arm lengths.
For maximum shot accuracy, the bottom of the golf club head, called the sole, should be perfectly parallel to the ground right at the moment of impacting the ball. To make this happen, Ping manufacturers its clubs with varying lie angles between the shaft and the head to compensate for each golfer's unique swing.
During their swing, taller golfers will change the lie angle versus shorter golfers, as will golfers with longer or shorter arms than normal. Ping manufacturers clubs with lie angles that vary from standard and indicates the degree of alteration with the system of color-coded dots. Golfers find the color that matches their particular measurements, and the result is a set of irons perfectly fitted to a golfer's particular swing.
Golfers can download a color-coded chart at Ping.com that explains the fitting process. The black section on the chart is the standard setting, with the colors above and below indicating the degree of variation in the lie angle based on the golfer's unique measurements.