Facsimile machines are rapidly becoming essential business tools alongside telephones, photocopiers, and computers. Some of you may be wondering whether to buy a fax machine; others are planning to add to the ones you already own. In a previous column I covered the basics of what to look for in a fax (see "Fax Finding," November 1988, [Article link]). Since then some other questions have come up.

I'm starting my own business on a shoestring budget. Which should I buy first, a fax machine or a photocopier?
The nature of your business may make the decision for you. For the typical start-up, a copier is probably more immediately useful. But if you are going to do a lot of business with people who already have fax machines, then you probably should get one, too.

If you have roughly equal needs for a fax machine and a copier, practical and economic issues argue for buying the fax machine first. Public copiers are common, and chances are you can find a place nearby to make copies for a nickel or dime a page. If you have your own small copier, your cost isn't much less -- about 2¢ to 5¢ a page. Public fax machines, on the other hand, are still uncommon, and the charges are high -- typically $2 to $3 a page to send and receive a message. With your own fax machine, the costs are zero to 20¢ a page to send (simply the cost of the phone call) and 2¢ to 10¢ a page to receive (the cost of the paper).

Anyway, all fax machines can pinch-hit as copiers, although copy quality is poor.

Which of the innumerable features trumpeted by fax advertisers do I really need to serve my small office?
Only two features are absolutely essential. You must have compatibility with the Group 3 international protocol, which incorporates standard and fine resolutions; all fax machines currently produced meet this standard. Avoid old machines that were built to the much slower Group 2 specifications, no matter how cheap they are. And the fax machine should operate at 9,600 bits per second (BPS, sometimes referred to as baud), so a typical page transmits in 20 seconds or less. Group 3 specs allow faxes to operate at 9,600, 4,800, and 2,400 BPS. Only a few 4,800-BPS machines are left on the market, but they are no cheaper than faster models, so there's really little point in buying one.

Two other features are so convenient that you could consider them essential. A document feeder saves you the trouble of hand-feeding pages into the fax machine one by one. A feeder that can handle up to 10 pages at a time is usually enough for a small office, while a 5-page feeder might suffice if you are on a budget. An autodialer stores frequently called fax numbers; you recall them by pushing one or two buttons.

Three more useful features are not as critical. A built-in paper cutter is handy for slicing an incoming fax into pages, especially if you get lots of long transmissions. A machine that accepts large rolls of paper will run out less often -- convenient if you expect to receive a great many faxes. And finally, if you expect to send pictures, your fax machine must be able to handle shades of gray, or halftones.

Though manufacturers tout many more features, few offices, large or small, ever use ones other than those listed above.

What's the best guide to fax machines?
The fax issue of What to Buy for Business ($18 from What to Buy for Business Inc., 350 Theodore Fremd Road, Rye NY 10580).

Does it make sense to get a fax modem for my computer instead of a fax machine?
A fax modem makes a poor substitute for a standard fax machine, because it is good only for sending documents that are already stored in a computer. To send anything else you would need a scanner (which is expensive), and even then, you would have to go through several steps to scan the original into your computer and get it into a form that the fax modem can process.

For receiving faxes, fax modems are nearly hopeless: you would have to leave your computer on 24 hours a day, and the printed output would be much less legible than what you would get from a fax machine. Most computer printers are too slow, and the dots they print are either too big (ordinary dot-matrix printers) or too small (most laser printers). You don't even need a fax modem to send text that is stored in your computer. Many public electronic-mail services accessible by ordinary modem can forward your message via fax.

I need to fax a confidential letter, but I know the receiving fax machine is in plain view of anyone walking by. How can I get around this?
For foolproof assurance, call ahead and make sure the recipient is standing next to the fax machine when your letter arrives.

You could try two alternatives, depending on the capabilities of the fax machines involved. If your fax machine supports password polling (and not all do), the recipient can call your fax machine, enter a password, and receive the document -- providing you leave the confidential letter sitting in your fax machine, where it may also be visible. Or if the receiving machine can store incoming faxes in a memory, you can send your letter with a password, to be stored rather than printed immediately; the recipient can print the letter only after entering another password.

To try either of these, both you and your correspondent will need to study your fax manuals. So unless you need to send confidential messages repeatedly, you will probably find it easier just to call ahead.

To fax photographs, what special abilities does my fax machine need? What about the receiving machines?
The sending fax machine -- and only the sending machine -- needs to be able to handle shades of gray. It converts the grays in the original artwork to patterns of black dots that all fax machines can use to simulate grays in the printed transmission. Therefore, on the receiving end, any fax machine will do.

The cheapest fax machines can send only black and white. Most fax models can send either 8 or 16 shades of gray. For typical business graphics, 8 are sufficient; 16 is better if you are sending photographs. The best results are produced by two Canon models (FAX-270 and FAX-705) that can send 64 grays with error diffusion, part of the UHQ process, which reduces patchy areas in the copy. Although not quite as good as Canon's, Ricoh's models with 64 grays are effective.

My fax copies are sometimes marred by glitches that show up as horizontal lines. What can I do to prevent this?
Momentary noise in the telephone line produces a horizontal line in fax copy; these lines are more visible in pictures than in text. A fix for this does exist: the International Consultative Committee for Telephones and Telegraphy (CCITT), in Geneva, which sets fax standards worldwide, has an error-detection-and-correction protocol that compensates for phone-line noise. The scheme works only if both sending and receiving fax machines have it built in. But the protocol is present in just a few of the more expensive machines; it can't usually be added to an older model.

People have to wait in line to use our fax. Should we get a fancier machine with, say, memory and delayed sending, or a second machine?
A second machine. Two inexpensive fax machines operating simultaneously will always outperform a single high-end unit, because the limiting factor is not the fax machine but transmission speed over the telephone line. Sending or receiving a page takes about 20 seconds no matter what kind of machine you use. Slightly faster speeds can be achieved, but only if the sending and receiving fax machines are the same brand; sometimes they have to be the same model.

The company that sold me my fax machine says that because of differences in the quality of fax paper, it will not honor my service contract unless I buy my paper from it. Is this reasonable?
No. The price of fax paper varies much more than its quality. A small (99-foot) roll of fax paper can sell for as much as $15 from a stationery store or as little as $3 from a discount outlet. Some people claim that cheaper papers vary in quality a little more than expensive papers, but such differences rarely cause problems. The really bad papers that were once around have all but disappeared. At any rate, you probably don't need a service contract -- fax machines are reliable products. If you are told that a particular model really needs a service contract, look for another one.