Type 1: The loop of the "9" of "1920" is large, the tail is small and tapers to a point below the center of the figure.
Type 2: The loop of the "9" is small, the tail is not tapered and extends the full width of the figure. This type was produced by two methods:
Plate A, lithographed, sheet about 203×253mm, block 39×49mm
Plate B, offset printed, sheet about 205×252mm, block 39¼×49mm
It is difficult to measure the small difference in blocks.
Identifying the Plates of Type 2 by Flaws
Plate A: seals #7, 17, 27, 40, 57, 67, 77, and 90 show a larger than normal dent in Santa's cuff to the right of the boy's elbow. On #23, and 73 Santa's right eye is almost missing. On #36, and 86 there is a blue dot on the boy's shoulder above Santa's hand.
Plate B: #34, 35, 84, and 85 the left end of the lower arm of the cross is rounded. On #35, and 85 there is a spur on the first wrinkle of Santa's left coat sleeve, near the right side.
Greens Catalog of the Tuberculosis Seals of the World,, Part 1, U.S. Christmas Seals, 2014 ed., p.20