By John N. Maclean, Chicago Tribune Knight-Ridder/Tribune Business News

Mar. 20--Click. The regular working day just ended, but your brain's still functioning and it just coughed up an idea. You fire up the computer and go on-line from Peoria to Chicago. Your computer hums a message to you saying it's ready to go.

Click. You pull up your company's data base, stored in a stack of computer gear the size of a filing cabinet at a prepress shop in Chicago. Your bright idea involves manipulating images in your catalog advertisement to give more prominence to an item you think will be hot; you pull up that page of the catalog, retrieve a stored photo image and go to work.

Click. You ask for a color proof sheet, usually a 24-hour process at minimum, and head for home. By the time you arrive back at work the next morning, you have a color proof chugging out of your printer.

The above scenario, which is beginning to happen, will redefine print data distribution.

``We are talking to clients about giving them control of...data,'' said John Gagliano, executive vice president of ASG Sherman Graphics Inc. of Chicago which has begun a program to educate its clients about their options. ``A lot of other prepress companies think they are above this in a high tower. The tower is falling.''

The tower is falling so fast some fear it may mean an end to much of the prepress industry as catalog and retail customers put together their own prepress operations. Prepress loosely means the preparation work required to get color jobs ready for printers.

It's not for everyone, of course. The basic printer costs about $150,000; a printer with higher quality required for some jobs can cost $500,000. And the entire system has to be customized.

Only companies doing a lot of business with a single graphic arts shop will be getting involved at this level of technology. But the technology does work.

The prepress industry finds itself in a paradox. Business is growing, if not booming, but traditional prepress is becoming the buggy-whip works of the 1990s. Sales for prepress services grew by 10.8 percent in 1994, according to a survey by the National Association of Printers & Lithographers. But this includes a strong gain - nearly 20 percent - in prepress work done by printers. Trade shops, by contrast, saw business grow 8.6 percent overall,

indicating strong growth but not on the scale outside the traditional shop.

The driving force for all this is the desktop computer, which has made it possible for customers, service centers and most prepress shops to make up jobs with all the advantages computers offer - more speed, more precision,

more ways to manipulate image and text and so on.

``Today's color prepress market is one of the most complex business environments operating in the 20th Century,'' wrote Louis Laurent, president of LAI business and sales consortium, in Prepress Market Watch, a publication of the NAPL. ``Press shops will have to take proactive steps to drive their business forward.

``Rather than surrender to obsolescence, prepress houses should take this challenging opportunity to capture emerging markets.''

One way to capture new markets is to go into the customer's office, already set up with a desktop computer, and offer more equipment and services. ASG Sherman has no exclusive hold on the technology, though it is more aggressive than some other companies.

R.R. Donnelley & Sons, which used to call itself the world's largest printer but now talks about international information transfer, increasingly consults with customers about ways for them to do more prepress work in- house. This year it helped one customer set up its own complete prepress shop in a deal that provided Donnelley staff and equipment onsite for a multiyear contract. Donnelley declined to identify the customer, but others are sure to follow.

``A lot of people go to trade shows, see what can be done technically and want to take on more responsibility as a publisher,'' said Amy Wittenberg,

publishing and prepress consultant for Donnelley. ``But there are a lot of issues here.''

Wittenberg and others, including ASG executives, said any business looking to take over more of its prepress work should know it needs to be on a fiber-optic cable. If it publishes only a few times a year, such as a seasonal catalog, it will have a lot of downtime for expensive equipment.

Despite the problems, the changes already are well under way. ``We're getting a lot of inquiries,'' said Wittenberg. ``People want access and control over their data.''

ASG calls its system Digital Interlink and has begun talking with customers about whether it would be appropriate for them. ASG also has had an advertising agency, the Wittleder Co. of Chicago, create an electronic presentation on its Interlink system that the company hopes to make available on-line to potential customers through the Internet.

By clicking through the program, print buyers can learn the basics about Interlink and ASG, then print out a fax sheet and send their contact numbers to ASG for follow-up.

``Potentially there are lots of advantages,'' said Charles Sherman, president of ASG. ``For big companies, it makes it easy to open a branch office - with a Macintosh and a printer the branch can tap into a main data base.

``You do save at least a day, which is important for some customers. You can move data reliably in bad weather like a Chicago winter.'' END!B&3?TB-COMPUTER-PRINT

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