With a Fax machine it is easy to send documents over phone lines. Faxing is a faster option than regular mail and an affordable alternative to overnight
delivery. A fax machine scans each outgoing page and converts the images into a series of light and dark dots. This pattern is then translated into audio tones and sent over regular phone lines. The receiving fax machine "hears" the tones, pieces the grid together, and prints the total compilation of dots. What you get are black and white copies of the original pages. When buying a fax machine, look into the following:

• Look for a model with the lowest available power level in "sleep" mode, because most fax machines are in standby mode most of the time.
  
  
• Consider a fax machine that scans duplex (two-sided) originals; this avoids the need to recopy a two-sided document before faxing it. Some models also offer two-to-one image reduction for incoming faxes; this reduces transmission time and saves paper.
  
  
• Make sure that the power management features of your fax machine have been "enabled."
  
  
• To save on both paper and energy, use stick-on labels in place of a separate cover sheet for outgoing faxes.
  
  
• Consider using waste paper with one blank side for receiving faxes.
  
  
• Sending speed: Fax machines with higher sending speeds, though more expensive, will often pay for themselves in reduced phone charges. The majority of fax machines transmit at speeds of 9,600 or 14,400 bits per second (bps). Faxing at 9,600 bps takes 15 to 60 seconds per page. A transmission standard called V.17 helps send faxes at 14,400 bps, reducing the sending time for a single page to six to 10 seconds.
  
  
• Data compression protocols reduce the time it takes to send a page by describing it with a minimum amount of data. You can reduce transmission costs by buying a machine with advanced data compression protocols. Virtually all fax machines are equipped with a basic compression protocol called Modified Huffman, or MH. However, machines equipped with the more advanced Modified Read (MR) or Modified Modified Read (MMR) protocols can send documents as much as 25 percent faster.
  
  
• You can choose from a few types of fax printing technologies:

Thermal printing uses a small heating element within the machine to mark heat-sensitive paper. It has a few drawbacks. Because they're stored on rolls, all your faxes will be on curled paper. The waxy coating on the paper is hard to write on, and the ink fades with time. And if the paper is exposed to too much heat, it will darken completely.

Inkjet: The least expensive types of plain-paper fax machines print using inkjets. Although very slow, inkjets produce relatively crisp text. The drawback is that it takes time to print out the text.

Laser: A more expensive type of plain-paper fax uses a laser or LED (light emitting diode) printing engine. It produces high-quality images with toner on plain paper. Laser/LED printing is quite reliable, with few service needs beyond toner and paper. However, they are much more expensive than thermal or inkjet machines.

• Memory lets a fax machine store incoming or outgoing pages without relying on paper. The amount of memory required to hold a page depends on the density of the image. In general, however, you can expect 512 kilobytes to hold about 20 to 25 pages. There are three common types of memory features:

Out-of-paper reception. This is one of the most useful memory features because this saves incoming faxes in memory if the machine runs out of paper.

Quick scan. With this feature, you can scan a page into memory before beginning a transmission. The advantage is that you don't have to wait at the machine until it finishes sending the original.

Dual scan. This capability uses memory to let you send and receive faxes at the same time. For example, you can scan an outgoing fax into memory while a fax is being received. The scanned fax is then sent directly from memory when the phone line becomes free.

• Multifunctional devices: Many fax machines can be connected to a computer to serve as a printer and/or a computer scanner.
  
  
• Legal-sized faxes: Firms that receive faxes on legal-sized paper should look for a machine with two paper drawers. This will allow legal- and letter-sized faxes to be printed on the appropriately sized pages without switching paper trays.
  
  
• Service contracts: If you expect to receive more than 50 faxed pages per day, make sure you have a service contract in case of a breakdown.
  
  
• Incoming fax pages: Some fax machines print the pages of incoming faxes last page first. This means, you'll have to rearrange the pages in the correct order before reading. If you find this bothersome, don't get a machine with this feature.