Doubled Dies: Class I (Rotated hub Doubling) (LINK):
Probably the easiest to conceptualize and diagnose. It is simply two separate hubbings, where the second hubbing has been rotated in relation to the first hubbing at or near the center point of the die. They are listed as clockwise (CW) or counter-clockwise (CCW) which pertains to the order in which hubbings were made; the deeper hubbing, which appears visually on top of the first, is typically regarded as the second hubbing.
Doubling is typically found to be rounded, with notching, seperation lines and extra thickness.
Below is a overlay diagram of a fictitious Class I Doubled Die that has a CW rotated spread similar to the King of Doubled Dies, the 1955P DDO-001. Notice how the spread is equal on all devices and increases further out from the center of the coin.
Below are photos of 1972P DDO-001, a Class I DDO with a strong CW spread on all outside devices and parts of the vest. Due to the way a second hubbing eliminates parts of the design impressed from the first hubbing, doubling typically only shows in areas that remain open in the new orientation of the die, thus, only the outside elements of the portrait of Lincoln and the motto show doubling while the center points are lost to the second hubbing.
You can see on the first hubbing G (1.) was entered along with the rest of the design, then the second hubbing was oriented CW to the first and the second G (2.) was hubbed. The second G visual appears to be sitting on the first G.
Below you can see clear separation between the letters in the motto.
Below is distinctive notching on the upper and lower serifs of the date (the 1 is highlighted).
Below is a Class I Doubled Die on the reverse, listed as 1964P DDR-001, it shows a CCW spread. Again there is clear separation, notches and rounded doubling – it is strongest in STATES and of. Notice that while all devices show some doubling, the upper motto is the strongest, this is due to the pivot point between hubbings, while near the center, being located over the steps rather than the absolute middle of the die.