Matching Pair Misprinted 1 Dollar Bills

Quote:
Currency production
Plate capacity on power presses increased from four to eight notes per sheet in 1918 in order to meet greatly expanded production requirements related to World War I.
With the dramatic redesign of currency in 1929 -- the first major change since paper currency was first issued in 1861 -- note design was not only standardized but note size was also significantly reduced. Due to this reduction in size, the Bureau was able to convert from eight-note printing plates to twelve-note plates. The redesign effort came about for several reasons, chief among them a reduction in paper costs and improved counterfeit deterrence through better public recognition of currency features.
A further increase in the number of notes per sheet was realized in 1952 after breakthrough developments in the production of non-offset inks. Beginning in 1943, the B.E.P. experimented with new inks that dried faster, therefore obviating the need to place tissues between sheets to prevent ink from offsetting to other sheets. The faster drying ink also enabled printed sheets of backs to be kept damp until the faces were printed, thereby reducing distortion caused by wetting, drying, and re-wetting of the paper (sheets needed to be dampened before each printing).
By reducing the distortion that increases proportionally with the size of the sheet of paper, the Bureau was able to convert from 12-note printing plates to plates capable of printing 18 notes in 1952. Five years later in 1957, the Bureau began printing currency via the dry intaglio method that utilizes special paper and non-offset inks, enabling a further increase from 18 to 32 notes per sheet. Since 1968, all currency has been printed by means of the dry intaglio process, whereby wetting of the paper prior to printing is unnecessary.
Currency has since been printed primarily by the intaglio method, whereby fine-line engravings are transferred to steel plates from which an impression is made on sheets of distinctive paper. Ink is applied to the plates -- each plate containing 32 note impressions -- and then wiped clean, leaving ink in the engraved lines. The plate is pressed against the sheet of paper with such pressure as to actually press the paper into the lines of the plate to pick up the ink. Both faces and backs are printed in this manner, the backs being produced first. After the faces are printed, the sheets are then typographically overprinted with Treasury Seals and serial numbers.