Carbon paper has been used for many years to make copies of documents while they are being written. It is still in use, but on a less regular basis than in the past. Duplicate checks use carbon paper, along with those triplicate forms that people use, such as when filling out job applications or other documents.
Carbon paper itself is fairly simple to make, even if it is not so easy to keep. All it is, is a thin piece of paper, covered on one side by ink or carbon (hence the name) that is loosely held to the paper, and together, with wax. The ink or carbon will be transferred to another sheet of paper which is placed under the carbon sheet; what is to be copied is placed on top and then traced. It is also possible to write or draw directly on the non-ink side of the paper to get the transfer. There is a limit to how many sheets of carbon paper can be stacked to create transfers. The limit is four or five depending on how hard the paper is pressed; after that it can become unreadable.
Though carbon copies have been largely eliminated due to electronic means such as photocopying, or printing multiple copies to start with, it has retained some uses, such as point-of-sale slips and duplicate checks. However, there are downsides. Carbon sheets can be a messy business, especially if they are not well made and the ink or graphite is not firmly attached to the paper.
The process of copying something using carbon paper is known as carbon copying, and the carbon sheet is usually put between two regular pieces of paper. Today the abbreviation of carbon copy, cc, is used in email when someone other than the first or primary addressee is going to receive the email.
It is still fairly easy to find carbon paper, as many office and art supply stores still carry it. When using it, it should be noted that the user should be careful with how he handles the paper so as not to get the ink everywhere. Today's more modern uses of the paper are to transfer tracings from one place to another, or possibly to draw a pencil or ink line onto fabric.
Though most of the uses of carbon paper are now outdated, it is not going away anytime soon. It is still useful in many ways, and its ease of use is always a plus.