No Lethargy for Letterpress
Letterpress printers should stay sharp on options in combination process, web widths, and overall press design.
By Susan Friedman
Package printers who have grown sleepy at the helm of traditional letterpress operations should perk up: developments in various combination platforms, wider webs, and in-line designs could offer new business opportunities.
The potential for specific printing processes to partner with letterpress appears intriguingly open-ended. According to John Little, president of Nilpeter, UV screen and hot stamping are its most common complements, with UV screen typically used to lay down a solid white background or solid borders.
John Warwick, sales director at Ko-Pack, reports his company's letterpresses are combined most frequently with a UV flexo varnish station. "As for combining printing processes, it is very rare to combine UV flexo with UV letterpress," he notes, "because the quality of UV letterpress still exceeds the quality of UV flexo. The only advantage to combining the two would be for printing a very large solid."
Combination trends at Taiyo Kikai reveal a different perspective. "We are seeing more flexo units with letterpress because of UV technology," reports James Willingham, product manager. "We find customers are opting for flexo in lieu of screen because of quality, increase in production speed, and advances in plate technology."
If a range of combination process preferences continues to co-exist, can the same be said for web width configurations?
Little contends 8", as well as 11 1-2 to 12" widths, remain the most popular letterpress configurations. "Some suppliers have tried to go to 16", but at this width, offset is more suitable in terms of volume to fill the press, and return on investment," he states. Nilpeter treads the middle ground by offering a letterpress cassette on its 13" M-3300 combination platform press.
Gallus, too, has long favored the 8" width on its stack letterpress design. "Stack and central impression (CI) designs haven't, for the most part, gone wider because prime label production runs haven't typically dictated such a move," explains Sales Manager Bob Yates. Gallus' new RCS-330 press will combine a wider 13" web with an in-line design to offer more convenient interchangeability of print methods, diecutting, and hot foil stamping units.
Other suppliers take slightly wider stances. Willingham says the most common press width for Taiyo is 10". "This width will always serve its purpose in the industry, but we do see presses going wider, to 16", because of the development of different materials being affordable, advances in web tension control and register, and quality control in manufacture," he adds.
Ted Fujita, VP at Sanki USA, concurs. "Ten inches is our most common seller, though the last seven presses sold have had wider widths—with one as wide as 16"," he relates.
Design differences
The numerous factors that separate letterpress's three design camps—stack, CI, and in-line—require printers to prioritize size, price, maintenance/set-up, and flexibility.
According to Yates, stack design advantages include a smaller floor space requirement (similar to a CI press), UV curing units at every station, chill rollers after every unit to eliminate heat issues, portability, 15-minute changeovers, and visibility of the web at every station.Part of the CI press contingent, Fujita highlights this design's better print-to-print registration. "The waste factor also is much less," he elaborates. "It is much easier and faster to get into registration and to achieve accurate color reproduction." Fujita says the CI press also allows the operator to clean multiple stations at one time.
"Central impression designs offer space, tighter register, and versatility for a wide range of jobs with a narrow web," seconds Willingham. Taiyo's CI offering includes letterpress and flexo, with stacked flexo units to provide more working area, while still saving shop space.
Warwick believes CI presses' tighter registration (accomplished by preventing movement of the material once it's wrapped around the CI drum) is particularly beneficial in today's market tendency toward film and plastics. "An in-line press needs more elaborate controls to hold registration because any type of heat causes the material to stretch," he notes.
From his corner of the in-line ranks, Little acknowledges CI presses are about half the price of in-line designs, but in-line comes up stronger in the categories of fast makeready and less maintenance. In-line users need only replace individual impression rollers—a smaller undertaking than replacing a CI drum.
While in-line stations can be moved to any position on the press, a CI design's situation is more fixed, Little emphasizes. Adding stations may require adding an entire press unit, and hot stamping units must be located at the end of the press unit.
In addition to touting printing station flexibility, Yates underscores such in-line design advantages as portability of inking units, higher productivity with more curing units, easier handling of multiple webs, and easier accommodation of wider webs. Disadvantages can include press length. "More web can increase waste, and cost," he comments.
