As far as printing processes go, gravure is one of the simplest. It is a direct application process, meaning ink is placed directly onto the substrate without having to go through the more complex methods that flexo and offset require. Though it may be a simple process, gravure is still not used extensively in the narrow web industry. The companies that use it are usually larger ones and tend to produce complex labels, such as those that include metallics.
The Supra Series, the latest from W.R. Chesnut Engineering, which is available in 16" or 25" web widths
According to Dick Chesnut, president of W.R. Chesnut Engineering Inc., a maker of gravure presses located in Fairfield, NJ, USA, solvent and water based inks are the most common ink types that converters use with gravure presses. He adds that gravure will also print UV ink.
Claus Larsen, market support manager for Nilpeter, a press manufacturer in Slagelse, Denmark, says, "Gravure ink is characterized by being very liquid (low viscosity). This is primarily due to the high solvent content. UV based gravure is something that was discussed in the R&D departments in the past. Today, the initial justifications for developing such a technology have been muddled by the qualities of today's flexo."
What about cost differences? Chesnut says, "Today, there's a wide range in cost with regard to sophistication, but gravure presses are typically no more expensive than flexo presses. And they're probably less costly than offset presses."
Although the initial press price may be comparable, cost is often seen as an issue for converters. Gravure can be more expensive in the long run. Steve Leibin, sales manager for Matik North America, a distributor for Omet presses and other equipment located in West Hartford, CT, USA, says converters have to buy gravure decks and if they are using solvent inks, the press needs to be explosion proof. He says costs increase with the additional processes associated with gravure and solvent inks, including drying time.
Those in the industry may be noticing several developments with regard to gravure printing. Drillings says, "A common trend in gravure printing is the use of different types of inks. Seal-It is being asked by customers for scented inks, holographic inks, soft touch, and thermochromatic inks."
Chesnut points out something else: "Trends today that are particularly being pushed by the equipment suppliers are generally to continue to address the issue of reducing printing costs and to address issues of short run in packaging, which is still very important."
Sleeves are another area of interest with gravure. Larsen says, "Gravure printing presses used to be dominated by large and heavy cylinders that had to be transported around in a factory or between factories. Today, however, these heavy cylinders have been replaced by sleeve technology, which makes transport and changeover much easier and operator friendly."
Leibin explains that with traditional gravure cylinders, press operators have to take out the whole cylinder and shaft assembly and drop in a new one. Gravure sleeves slide onto the mandrel shaft. This lowers gravure cylinder costs. He says that with traditional gravure cylinders there is no mounting, but with sleeves, there could be. He explains, "Very often, if they're doing sleeves, they'll leave it mounted on a mandrel. If the job ends in two years, they can take the sleeve off and reuse the mandrel." Sleeves can save converters money with less gravure cylinder costs.
Another area concerning gravure that Leibin points out is combination printing. An example would be a press containing offset and gravure stations, which he says is at the high end of the label market. "On a combination press, each printing process brings specific benefits to the press. All the processes can give specific benefits to create all different types of effects on the label," Leibin says. Why are converters looking to combine several methods of printing? Leibin explains, "P&G, Unilver, Colgate, etc. are demanding more from converters because they want more shelf appeal. They're looking to the label to grab that attention. That means offering metallics that really shine, texture with a really cool feel to it and fine high quality printing. Putting that all together becomes very important."
Pros and cons of gravure
When evaluating what type of printing press to purchase, several issues need to be considered. Cost is one of them. Chesnut says, "Gravure is a lower cost than some of the other processes when used in specific ways. This is counter to what people believe. It's actually lower cost if you're doing repeating runs." Gravure cylinders can last for millions of impressions, so using gravure can save converters money in the long run if they have many jobs that are repeated. Chesnut also points out, "Gravure has been demonstrated on many occasions to be lower cost than competitive processes like litho and flexo because of the nature of gravure. It can produce certain imagery that other processes can't do as well, i.e., shiny metallic materials. Gravure is still the leader in that."
A rotogravure printed label. Photo courtesy of Seal-It, a division of Printpack Inc.
Quality is another pro. "Gravure offers photographic quality graphics with lifelike skin tones and fine details. There are no disadvantages as far as quality goes," says Seal-It's Drillings.
Larsen sees gravure inks as offering the most advantages. "The gravure ink is a relatively low priced product and hence, at times, an attractive alternative for coatings or to achieve metallic effects," he explains. "The gravure ink is the best alternative for metallic effects if one wants to avoid the downsides of hot foiling in very large volume runs."
Using solvent inks can also be seen as a disadvantage, however. Leibin explains, "There is a lot of fear about solvents because there are EPA regulations governing how much VOC emissions you can produce." He adds, however, that converters using combination presses with one or two gravure stations would be considered small generators by the EPA and wouldn't have many issues in that area.
Another concern can be complexity. Nilpeter's Larsen says, "Gravure is a relatively simple printing principle, however, as we in our industry need it in combination with other printing methods, suddenly incorporating gravure is not such a simple task. The risk of explosions is the major hurdle to cross, as narrow web presses, under normal circumstances, are not made to work in such solvent saturated environments."
Although in certain instances gravure can cost less, initial investment can be seen as a disadvantage. Leibin says, "With gravure, you have to buy engraved cylinders or sleeves. That's costly compared to flexo plates. Most converters cannot do them in-house. They have to have them done in a prepress house."
Chesnut says, "A disadvantage of gravure would be that it's probably not the first choice for a one shot job. It's a better choice for a repeating run job, even if the runs are short. If you're going to run it once and never again, generally gravure is not the best choice."
Why not narrow web?
Gravure is certainly not the most common choice when converters in the narrow web segment of the industry buy a printing press. A very low percentage of narrow web converters choose it. Leibin estimates that 10 to 15 percent of the market segment uses gravure.
Larsen agrees that gravure, though increasing in popularity, still isn't that common. "There has been a significant growth in the use of gravure over the years; however, due to the cost of the hardware, the technique is still only used by relatively few printers with large or specialized production series," he explains.
Chesnut has a theory as to why gravure isn't used more extensively. "A lot of narrow web applications are relatively basic — tag printing, food labels, automotive. They really don't require the benefits that gravure would offer. Prime labels and health and beauty aids are big players, but it's a small part of the market," he says. He points out that most label producers are small companies that aren't necessarily involved in the more sophisticated segments of label printing market.
Leibin believes that learning how to work with gravure is an obstacle for some narrow web converters, even when working with combination presses. "It requires a whole other expertise," he says.
According to Drillings, cost could be a deterrent. "The misconception is that gravure costs more than flexo," she says, "but in the end gravure provides better quality and more consistency of overall print."
Although gravure isn't the most popular choice for narrow web label converters, those involved with the process see it as emerging. Certain applications can be better served with the gravure printing process. Chesnut says, "Shrink is dominated by gravure processes. It's a natural for gravure and a big growth area." He says shrink applications in the market as a whole are growing in the double digits while pressure sensitive growth is significantly less, at around 2 percent.
Omet's gravure cassette installed on the Varyflex Gearless-Shaftless sleeve flexo press
The desire for different looks may spur gravure growth. Larsen, of Nilpeter, explains, "The trend is definitely in favor of gravure in the label industry. There are a number of factors why this is the case today. The first and foremost is the special metallic effect the label printer can achieve with the use of gravure. The mirror effect is more and more sought after and a driving factor for use of this technology in narrow web label presses."
A converter might switch to gravure if he isn't satisfied with the capabilities of another printing process. Chesnut says, "If he's printing flexo and he has to do better than what he can do with his current equipment, then gravure should be considered."
Instead of switching completely over to a gravure press, converters may look to the combination presses with gravure stations. Leibin says, "The ability to slide a gravure station into any station on the press offers tremendous flexibility. What we see in the shrink label market where customers want metallic laydowns, is that it's very difficult or impossible to achieve with any other print process except for solvent gravure." He adds, "Sliding gravure in when needed allows converters to offer new things to their customers — unique or new constructions. They have another weapon in their sales arsenal."
In the future, the narrow web label converting industry will probably see more gravure use. Larsen says, "On a year-to-year basis, Nilpeter is experiencing more and more demand for incorporating one or more gravure stations across the range of our presses, and we do not expect this upward trend to change anytime soon."