"Protectograph Model H C.W Todd & Company No. 224429 Rochester, N.Y, U.S.A
A small black machine known as a protectograph. It has a large white dial on the one side. On the top there is a lever that you push down.
A check writer (also known as a "ribbon writer", "check signer", or "check embosser"), is a physical device for protecting a check by preventing the monetary amount for which it was written from being raised or altered.
Devices of this type that use various technologies are also known as check protectors, check punches, and check perforators. A check punch punches holes in the shapes of numerals. A check perforator punches small round holes that form numerals.
A check writer, or ribbon writer, leaves a numerical or written value impression in the payment amount field of a check that is very difficult to alter. This is accomplished by the machine applying downward force on the check and leaving very small inked shreds in the paper.
The first check protector was introduced in 1870. The best known check protectors in the early 1900s had the brand name Protectograph.
The person preparing a check positions the check in the check writer so its print-heads are centered over the field on the check where the amount of the check would otherwise be written out in words. Using a series of levers or buttons on the checkwriter's control panel, the operator enters the monetary amount of the check. This amount is then printed onto the check by the operator pulling a lever on the side of the unit (or by pressing a button on electric units). This brings the print-heads down upon a wide inked (usually multicolor) ribbon through which they print the selected amount on the check, with a prefix and suffix to prevent a fraudster from adding extra digits.
There is a series of (usually) horizontal indentations on a pressure bar brought up underneath the check during this process, which matches similar indentations on the print-heads. This embosses the numeric amount through the paper of the check form, strongly discouraging any attempt to alter or raise this amount.