A systematic and rational classification of the three cents (both rose and brown) and their congener the six cents (purple and rose) is now ready. The collector of entire envelopes will proceed as follows:—
Given a certain specimen, he first ascertains the knife, second the color of the paper. He then decides which head is represented, and finally ascertains whether it is an "A" or "B" die. The specialist, or any collector who is sufficiently interested to possess the various sub-varieties, goes a step further. Having determined the head, he finds to which of the four classes of line measurement a given specimen belongs. Thus the apparently bewildering number of varieties, through the knowledge of the heads and the "U" line measurement, are brought into perfect order, and all risk of confusion is avoided. It is evident that, henceforth, the collector of cut squares will try to obtain at least one specimen of the different heads of both die A and B, while the collector of entires may go to any length to satisfy his zeal and ambition.
The large die (Die B), measuring horizontally 25-1/2 mm. or more, is comparatively scarce and it is found most commonly on the small envelope, Knife 22.
THREE CENTS, ROSE.
| K. | 22 | Heads | 1, 2, 4 | White |
| " | 11 | " | 4 | Buff |
| " | 9 | " | 1, 4 | White |
| " | 9 | " | 1 | Buff |
| " | 12 | " | 2, 4 | White |
| " | 12 | " | 2 | Amber |
THREE CENTS, BROWN.
| K | 21 | Head | 1 | White |
| " | " | " | 1, 2 | Buff |
| " | " | " | 2 | Amber |
With the issue of the three cents, rose, the contractor, at the order of the Post Office Department, introduced a second quality of buff paper. This matter is of importance to all collectors and should be duly noted.
In a circular letter from the Finance Office, dated "Washington Oct. 1866," signed "A. N. Zevely, 3d Asst. P. M. G.", it is stated:—
"Letter size envelopes stamped 3 cents, made of a cheaper quality of paper than those hitherto furnished, are furnished by the Department at $32.80 per 1,000."