This is one of the most difficult values to type on account of how little the colors varied through the years. The least common printing is the typographed stamp on 1E1 paper.
Here I show a sample of these stamps showing the watermark. Notice las middle stamp is short, maybe from a perforation error sheet.
Here I show a few blocks of four on several papers. The colors are filtered by the Photoshop 'equalize' function. The 1E1's after this filter look golden, and the 1E3's look darkened, even though the latter paper is white.
The 1c 1E4 is bright white and thin, and is usually perfed comb. This perforation format is found on the other 1E4 values.
I show here a mint selection. First image is front, second is back filtered for watermarks, and third is back showing the gum, all stamps matching their relative positions.
The cream paper of 1936 has darkened gum, although it is unclear to me how much of the color is the gum, and how much the paper. The later gums are shiny and white.