Packaging Workflows
New Screening Technology Delivers “Stunning” Improvement in Output Quality of Flexographic Printing

As a package designer, you work hard on your creations. You labor in your studio, a nearby park, the subway—wherever you do your most creative thinking—and you want every package to look its best when it is finally reproduced. But, we know what it’s sometimes like: you ponder, you brainstorm ideas, you finally get the client to agree on a vision, and when you see your artistry—the result of your hours of labor—it isn’t quite what you envisioned. Perhaps the image is a little muddy; the color is off; or the detail is, well, not as rich as you would have preferred.

What if there were a way to ensure that what you envisioned and submitted was closer to your original than anything else you’d seen before? City Stamp Works (CSW), a packaging prepress provider based in Ludlow, Mass., fulfills that vision every day. CSW provides packaging design, proofing, and information technology services, as well as flexographic printing plates, die-cutting, and film separations to a spectrum of converters in both flexographic and offset packaging production. The company, which also does business directly with consumer product companies such as Nestlé and Bose, understands the critical nature of design capabilities from both sides of the supply chain.
Instead of jumping into technology just for technology’s sake, CSW’s approach has been to evaluate new systems on their ability to deliver specific improvements over current capabilities. CSW’s ability to critically analyze new products and services is what sets the company apart from the rest of the pack. CSW purchases a new technology not just because it’s the flavor of the day, but because it delivers real-world results.

Aim was to rival offset
One example of this systematic approach, which CSW calls Xtreme Technology, is the company’s evaluation of a technology that would deliver very high quality output for flexographic plates. CSW wanted its flexographic plates to match the quality of offset lithography at higher resolutions. The company evaluated a new screening technology by Agfa, called Sublima, that promised to deliver digital-like output from their conventional flexo platemaking system.

Sublima XM for flexo is an intelligent screening technology that combines the properties of AM (amplitude-modulated, or conventional) and FM (frequency-modulated, or stochastic) screening to deliver a new generation of technology known as XM (cross-modulated) screening. According to Agfa, the patented technology uses AM screening in midtones and an FM implementation in highlights and shadows, transitioning smoothly from one screen to the other.
Agfa says that Sublima XM can calculate the precise changeover point at which the image can no longer benefit from AM screening. First, the smallest reproducible dot that a specific press can hold is determined. When, during screening, Sublima XM reaches the level of the smallest reproducible dot, it no longer attempts to make the dots smaller. Instead, it uses a patented method to “take out” AM dots and replace them with FM dots. Though the resulting dots in the highlights might appear to be random, they continue to align along defined AM angles.

Laura Wright, left, president of CSW, and Frances Cicogna, Packaging Market Segment Manager for Agfa Corp., review pieces printed by flexography using Sublima XM screening.

Agfa says that because Sublima takes press characteristics into account, it compensates for dot gain and won’t produce a dot that the press can’t hold. This makes it possible to print every detail, including process tints, fine lines, and delicate typefaces. And because Sublima can hold the tiniest microdot on press, says Agfa, enlarging or reducing images has no effect on quality. This widens the variety of media that can be used at high line rulings.

To test the viability of these claims, CSW partnered with several converters that print on substrates such as flexible packaging and corrugated. The test used an image that required a resolution beyond anything ever attempted by the converters. It contained extreme highlights, fine detail with subtle colors, and patterns and textures that typically cause moiré when printed at lower line screens. The converters sequentially ran plates of increasing resolution without ever telling the pressroom staff what they were doing. At the end of the test, when the press crews were told that the last run had printed at about double the normal resolution, they were stunned.

So was CSW, which hadn’t expected the converters to be able to from 120 lpi to 212 lpi without having to make any changes at all in the pressroom. The pressroom operators didn’t know they were printing at 212 lpi until they measured the screens. This kind of systematic approach to evaluation and everyday operations is what gives CSW its competitive edge in the ability to exactly reproduce the visions of its packaging customers.

Technology is good when it can be implemented for a successful and profitable outcome. However, the creativity and sophistication of an organization are what deliver accurate reproduction. CSW’s internal talent ensures that the final product looks the way it was intended to look. The company’s creative staff also spends time consulting with designers to offer suggestions that can improve the final outcome. CSW’s intimate knowledge of the printing and converting process is an invaluable resource to the design community.

The conclusion: in an environment of heavy competition, where everyone is trying to stand out from the competition, there are technologies that can assist in producing more appealing output. It’s important to know what those technologies are, and who is using what. Since you want your image to be the best that it can be, make sure that your converter is doing all that can be done to ensure that your original vision is what ends up on the shelf. By using innovative technologies, you and everybody else will be able to see how real your visions can appear.