The 25c, 30c, 40c, 50c, 1p, and 2p are the values I plan to use for this topic. I have previously shown some of the 25c color varieties-for the 1E papers. First, its important to lay out the values by paper:
1. The 25c, 30c, 40c, 50c, 1p, and 2p on the 1E papers before 1945 (1E1, 1E2, 1E3, y 1E4)
When I separate these, each paper seems to have one color, and the same color is sometimes found on multiple papers.
2. The 25c, 30c, 40c, 50c, 1p, and 2p unwatermarked (NGR and NOP).
I find a wide range of colors for the 30c and 40c NGR. The other values seem to come in a single combination of colors.
3. The clays of 1943: 30c, 40c dark, 1p, 2p dark; These seem to come in a single combination of colors.
4. The clays of 1951/52: 25c official, 40c light colors, 50c (regular and official), 2p light colors; These seem to come in a single combination of colors.
I do not find any of these on the Straight Rays diffuse paper (2D)....I will keep looking.
5. clear Straight Rays (2C): 25c, 30c, 40c, 50c, 1p, and 2p; These seem to come in a single combination of colors.
6. The late Wavy Rays papers (1951 onwards): two or three papers for each value, except for the 50c with five papers.
For these I find a wide range of colors, especially for the 50c and the 2p.
How do we define the colors? This is a topic open to much disagreement. This is why I begin with an awareness of the papers. Each ink combination was used for a limited time period, usually coinciding with the use of one or two specific papers. For example, the 50c with yellow background was printed on one paper in 1956/57. If we use dated used stamps, we can establish these time periods.
I see three steps to define the colors:
1. The rare printings are trivial to define since there aren't any color varieties. This is the case of the clays of 1943, all rare.
2. A few printings are distinctive. These are the easiest to define. For example, all of these values were printed on deep/bright colors in 1943 on the 1E3 paper. A few of the last printings are also distinctive-for example, the 25c official from the 50s on 1L paper.
3. The more complicated to define are left for last. The printings of 1936/37 come to mind.