A fax machine employs a few neat technologies to transmit your page to another fax machine. First, the document is passed over a scanner. The scanner will build an approximate picture of the page made of black or white dots. Fax machines usually can scan at 150 or 200 dots per inch, depending on the setting. Finally, the receiving machine prints the page.
Most fax machines use thermal paper, which turns black where heat contacts it.
You can print on it with a strip of little heating elements that turn and off as the paper is rolled over it. Other fax machines use ink, toner or transfer ribbon as the printing technology. Copyright 1998-1999, Room103 group. Don't steal this. All rights reserved.