First invented in the mid 1800's, fax machines reached the height of their popularity during the 1980's and early 1990's, with their ability to encode and transmit data over a phone line and send it to another fax machine, where a hard copy of the data would be created. When fax machines first appeared, they were sold as individual units. Today, they are usually available in combination with printers, copiers, and scanners in machines known as multifunctional machines. Even though they are not as popular today as they were a decade ago, fax machines are still a valuable and necessary piece of equipment in today's businesses and offices. When it comes to purchasing a fax machine today, factors such as the speed of transmission, the type of printer the fax machine uses, amount of memory and the size of paper it can handle should all be considered. Transmission Speed - Sending a fax is not free, and usually has charges associated with doing so. As a result, choosing a machine that has higher sending speeds is key to saving money. Most fax machines send data at a speed of 36.6 kbps, which means they can send a page of data in about 8 seconds. Machines do not have to have the same speed in order to communicate with each other, although communication will take place at the speed of the slower model. Laser vs. Inkjet Printing - Fax machines come in both inkjet and laser printing varieties. Inkjet fax machines are usually slower, but produce good quality text and images. They are however, not designed for heavy use. Fax machines with laser printing capabilities are designed to handle more use and more wear and tear, but they do provide excellent image quality while requiring less servicing and repairs. Memory - The more memory a fax machine comes with, the more pages and incoming and outgoing data it can hold. A typical fax machine can store about two-dozen pages in its memory, and additional memory cards can be purchased in order to increase the amount of data it can hold. Memory on a fax machine becomes important when the fax machine runs out of paper, a paper needs to be scanned before being faxed, or when a fax needs to be sent out at the same time that one is being received. Paper Size - Before purchasing any fax machine, make sure that it is capable of handling the particular paper size(s) used in the office. Most fax machines are designed to handle standard 8.5 x 11 inch paper.