marks were applied either individually or on blocks of mint stamps with
the use of a stamping device. Examples of the individually struck
markings are the “OFFICIAL / BUSINESS” and “OFFICIAL / MAIL” types.
The first cover illustrated below show the blue “OFFICIAL / BUSINESS” mark
struck on the back of the cover instead on the 2c Washington stamp.
cover illustrate the “O.B.” mark struck directly on the envelope
using a stamping device capable of marking a block of 10 at a time. Although
the strike on the 2c franked cover show only a 3 x 2 purple marking, a
used 1901 4c Lincoln block of 12 illustrated in one of the pages in this
collection clearly show a diagonal “O.B.” impression on 5 stamps to a row
x 2 rows.