Custom Printing: Digital Ceramic Printing on Glass

I read a few articles online this week about custom printing on glass. My interest piqued, I did further research. What interested me the most were the facts that glass is non-porous and that printing on glass needs to be durable (after all, if an architect builds a structure and the printing on the glass panes degrades, it could be extremely expensive to repair or replace). So how can you print on glass in such a way that the image won’t scratch off and degrade? This was my question.

The History of Printing on Glass

According to my research, prior to 2007 the two methods for printing on glass were screen printing and digital UV printing.

The first option, screen printing, included both direct custom printing (by forcing ink through a stencil on a mesh screen) and transfer printing (printing on paper and then transferring the image to the glass substrate). In both cases, it was necessary to fire the glass, once printed, in order to permanently bond the ink to the substrate.

UV printing, on the other hand, came about much later, relying on UV light to instantly cure the inks. Unlike ceramic inks, UV inks just sit on the surface of the glass and are not permanently bonded to the substrate. Therefore they are not durable enough for exterior architectural use or automotive use. Although it is possible to achieve a wide color gamut and precisely detailed imagery, UV ink printing on glass is best used indoors.

Next Generation Technology

After UV inks and screen printing, the next technological advancement was the digital printing of ceramic inks directly onto the glass substrate, followed by the firing of the glass to permanently fuse the pigments to the substrate.

This provides several benefits:

1. 1. Unlike screen printing, digital custom printing with ceramic inks does not involve all of the makeready necessary with mesh screens. Therefore, the process is easier to complete, and short runs are economical.

1. 1. Like UV digital printing, digital printing with ceramic inks can achieve striking detail and a wide color gamut.

1. 1. Unlike UV digital printing (but like screen printing), the nature of the ceramic inks and the additional firing step following printing make the image on the printed glass extremely durable. Therefore, this process is ideal for both interior and exterior decorative and functional purposes. That is, you can print an attractive image on the glass (decorative), or you can print patterns that diffuse the light or reduce the heating effects of the sun (functional).

1. 1. Unlike screen printing, digital ceramic ink printing is easily repeatable. Therefore, if a printed glass panel is damaged, it is much easier to match the design and color of the original image when reprinting the new panel.

1. Technology is in use to seamlessly integrate the imaging software (the computer application in which you create the design), the ceramic ink printing equipment, and the digital ceramic inks. This affords precise control over not only the color but also the level of transparency/opacity of the printed glass substrate.

Uses for Glass Printing

To put this technology into context, here are some of the uses for commercial printing on glass, which can include text, images, or patterns:

1. 1. You can print an attractive design. For instance, you can create glass mirrors with subtle but detailed imagery to decorate the interior of an office space.

1. 1. You can print a functional design. For instance, if you have a meeting room with floor to ceiling glass interior windows and you want to give the people in the meetings a measure of privacy, you can print an image that reduces transparency, or you can print a pattern, such as a matte frosting, that merely increases the opacity of the glass without having a discernible image.

1. 1. You can use printing (such as patterns) to control the heating effects of the sun through exterior glass windows.

1. 1. You can use printing (such as patterns) to diffuse light.

1. You can reduce the chance that birds will fly into the windows.

How This Is Done

This is the science behind the art of commercial printing on glass:

1. 1. Image processing software (a raster image processor, of which Photoshop would be a more generic example) not only prints the ceramic frit-based inks but also controls their application (thickness of the ink film, for instance) based on desired levels of transparency/opacity and the size and thickness of the glass substrate. (Frit is a temperature resistant ink containing particles of glass and ceramic as well as pigment. It is durable and abrasion resistant, and it helps adhere the ink to the glass substrate.)

1. 1. Digital ceramic frit-based inks are used based on the CMYK color model. The frit-based inks contain ceramic frit and inorganic pigments. These are fired, after printing, to fuse with the glass. During this process, the intense heat decomposes the inorganic additives and binders in the ink. Then the heat fuses the frit to the glass and the pigments, expels any voids to compact the ink film, and forms “a bubble-free layer of constant thickness and homogeneous pigment dispersion within the glass” (Wikipedia).

1. The third element is the ceramic ink printer, which is a flatbed digital printing device with print heads that move over the rigid surface of the glass, spraying the pigmented ceramic inks onto the substrate. Inline drying elements immediately fix the drops of ink in place, allowing for single-pass printing and sharp image detail. The precision of the printers (and the drying technology) allow for 720 dpi printing on substrates up to 10.8 x 59 feet (approximately), with vibrant hues, consistent and repeatable color, and fine detail.

The Take Away

1. 1. If you have design skills and experience, there are jobs out there. You can apply your skills to either aesthetic decoration of glass or functional design (which is another growing arena of commercial printing).

1. 1. The same thing is true if you have production knowledge and experience, and sales acumen. The field is growing (again, in both decorative and functional commercial printing), so there is an increasing need for sales professionals.

1. Or, if you are a production person (perhaps from an in-house prepress unit of a custom printing supplier), there are production jobs out there bringing together skills and knowledge in raster image processing, ink composition, the firing of ceramics, and digital printing equipment.

The marketplace is driving this growth in digital ceramic printing technology, and it seems to be on a tear.

This entry was posted on Sunday, December 2nd, 2018 at 9:47 pm and is filed under Printing on Glass. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.