Underprint patterns. These patterns were printed repetitively across a note or security, usually in a second color, to create a fine-line undertint that was difficult to counterfeit. The patterns on this proof are a little too large for a banknote and were probably used on a stock or bond. Revenue stamp fields. Around the time of the Civil War the federal government began imposing taxes on all manner of transactions. Checks, stocks -- even commercial photographs were taxed and required to affix a revenue stamp on the document. Banknote printing firms created ornate fields for merchants and bankers to place the stamps. Large corner elements. Larger elements like these were likely used on stocks and bonds, but could also have been part of engraved invitations, menus, labels, taxpaid stamps and other products. Sometimes geometric lathe work was incorporated, like the six-sided rosette on the left, but others, like the cotton flowers and buds, were entirely engraved by hand. Some banknote engravers specialized exclusively in this type of work.