Lately, Dell Inc. has been making up for lost time. Since it started selling Dell-branded printers a little over a year ago, shipments have risen at an encouragingly rapid pace. Mr. Dell predicts "tremendous growth" for his company's computer printer business over the next 5 to 10 years and vows to change the economics of the industry. Tomorrow, Dell plans to announce that it will begin selling printers for the corporate and home market that it claims will reduce the cost of some printing jobs by 30 percent or more.

Such talk sets Carleton S. Fiorina, the 49-year-old chief executive of the Hewlett-Packard Company, the powerhouse of the printing business, on edge. She regards Dell's declared ambitions as an irritating blend of hubris and hot air. Ms. Fiorina notes that her company's printers and cartridges, especially the inkjet printheads - clusters of nozzles, each smaller than a human hair, spurting out millions of superheated droplets a second - are the result of two decades of sophisticated semiconductor and nanotechnology research.