ABSTRACT
Prior to word processing, the act of writing required one of a succession of media that each made correction of errors, and therefore revision, more difficult. This was the price paid for equivalent increases in permanency in each stage. Pencil on paper, the medium most used now by children in school and adults for casual encounters with text, is the easiest to change, and the most perishable. Pens make scribbles and signatures that last far longer than those of pencil; but they are all but impossible to neatly erase, and, dependent as they are on the same physical skill of the handwriter, they are no more reliably legible than pencil marks. Typewriters create text that is much more legible, and more durable. But up until the introduction of self-correcting typewriters, at the very vestibule of the computer age, their impact on the page was flatly impossible to neatly correct. And the various modes of typewritten self-correction, prior to computers, could be defeated if an error was noticed after a page had been removed from the machine, or spotted after the typist had proceeded too far down on the page, or simply if more than one correction was needed in the same place. The target of all of these corrections-the bearer, after all, not only of their result but of the very physical changes entailed-was just a piece of paper.
