Printing Progress: Developments in Digital and Direct-to-Glass Printing

By Jordan Scott

Digital and direct-to-glass printing is no longer new in the glass industry. Since its first introduction to the market more than a decade ago, the technology is now well-established. That’s due to advances in speed and print resolution, as well as architects’ willingness to specify decorative glass for an increasing number of applications.

Starting Out Strong

Rather than being one of the first companies on the market with digital and direct-to-glass printing machines, companies such as Tecglass in Lalin, Spain, and Cefla in Imola, Italy, waited to develop what they consider more established technology.

Javier Fernandez, co-founder of Tecglass, remembers that, in 2009, his company offered a digital printing machine with 1,000 active nozzles per printhead and a resolution of 1,440 dots per inch (dpi). The company achieved this by focusing on research and waiting four years to enter the market, according to Fernandez. He says the printhead technology has been crucial in improving the machine’s speed and power.

“The one important factor that made the difference is the close cooperation and hard work with our suppliers and partners which made it possible to have compact printheads that place a lot of [nozzles] in a small space,” he says.

Cefla took a similar approach and entered the market after it had more time to mature. Silver Santandrea, research and development manager at Cefla, says that the printheads used on the market haven’t really changed in the past ten years. Instead, it’s the number that make the difference in speed. According to Santandrea, it’s possible to achieve 320 to 645 square feet (30 to 60 square meters) per hour with nine printheads compared
to just 21 to 33 square feet (2 to 3 square meters) per hour in the past with a single printhead.

It’s in the Ink

Santandrea says that as the company seriously considered entering the market, it focused on which ink to use. It ultimately decided to leave customers free to get their ink directly from a producer.

While the base colors are similar today to what was available ten years ago, metallic inks are starting to hit the market. Santandrea says these can be up to 15 times more expensive than conventional ink, meaning that fabricators want to avoid excess use during the printing process. As a solution, Cefla offers smaller ink containers so that only a small amount is used at a time in the printer.

“The metal ink is expensive and mostly used for special effects so only a small amount is needed,” says Santandrea. “We received requests from the market to create a solution so that they weren’t throwing away thousands of dollars of ink because they forgot to clean the containers.”

Fernandez says Tecglass offers a high flowrate ink recirculation system to avoid the need to clean the heads every day, eliminating ink residue and waste. The company offers gold, platinum and anti-slip inks. It also has inks for coated glass, frosted imitations, pure red and yellow, and has more in the pipeline. He expects the biggest evolution in the future to occur within ink and ink colors.

Santandrea says that with the original technology, the glass had to pass through a drying oven before it could be tempered, now the glass can dry on the printer before being sent directly into the tempering oven.

The Fabricator Viewpoint

The best way to gain insight into the advances in digital and direct-to-glass printing technology is to use the machines over a long period of time. GGI of Secaucus, N.J., first purchased a Dip-Tech direct-to-glass printing machine in 2008, and continues to use that manufacturer’s equipment. According to Stephen Balik, director of marketing and architectural sales, the company was one of the first to bring the technology into the U.S.

He says that the maximum printing resolution at the time was 360 dpi. The company upgraded its line in 2015 with machinery that prints with a resolution of up to 1,410 dpi. Despite the improvement in print quality, Balik says a major obstacle for direct-to-glass printing machines is the quality of the image files.

“Being able to print up to 1,410 dpi is reflective of the machine’s capability but not the quality of the files,” he says. “We’re converting existing artwork from a different format, often times from something not digital.”

Newer machines can also have up to 12 ink channels, which increases the printing speed, especially if printing in one color. There are only seven core colors but other colors are achieved through digital blending. Balik says the company’s original machine had half the number of ink channels.

“We’re at the mercy of how many different colors we can actually use at once,” says Balik.

He’s also noticed advancements in the speed with which ink colors can be changed. With GGI’s original machine the ink channels had to be removed, washed and reloaded. Now much of that process has been automated.

However, custom color matching still remains one of the biggest challenges in digital and direct-to-glass printing.

“That never gets easier because we still have to go through the process of
getting a digital file and converting it from a file to a piece of paper to glass,”
says Balik.

Another major advancement in direct-to-glass printing involves movement. The glass would move around under the printer with GGI’s first machine. Balik says that when printing on larger lites of glass that movement could lead to alignment issues. With the newer machine the glass stays stationary and the printerhead moves around. This allows the company more flexibility to print on large lites or on multiple small sample sizes at once.

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