Buying a Digital Press (Now)? -- Waldman
Like any offset press, these presses require an experienced pressman. With today's fast makeready procedures, imaging on the press is not an overwhelming advantage. Still, it has its points and should be considered carefully, particularly since it is less of a parameter change for the typical offset printer.
Dry or waterless digital imaging presses are very different from the wet variety and are a bigger parameter change for the traditional printer. You could say that waterless printing is more like gravure in concept than offset because the plate is etched. There is no ink/water balance so the first sellable sheet comes up very fast, usually in 10 sheets or less. There is almost no ghosting, solids can be quite intense and the presses can really hold a sharp dot.
These presses are also totally automatic in that they discard and load plates from commands issued on a computer console. In fact, plates and ink are loaded like supplies and the press runs with the simplicity of a digital press (almost). Most important, consumable costs such as ink are almost the same as a traditional offset press.
Waterless presses are rated to produce 30,000 impressions on a set of plates, but can go much higher and they do run at offset press speeds. Remember, though, that we're talking short runs, so that isn't as important as fast setup, which is usually around 15 minutes from the last sheet of the prior job to the first good sheet of the new job. Since so much is automatic, the operator can do other chores like load new paper, change supplies or prepare new files.
Because there are far less parameters to worry about, dry digital imaging presses don't require all the skills of a regular offset pressman. But don't hire a former hamburger flipper, because knowledge of color and ink on paper is more than just useful. The 74 Karat from KBA doesn't even have keys to adjust ink channels. This may shock many printers, but I think it is the correct approach as it fits the don't play at the press, just run, concept of short-run printing.