This article has been updated from a previous blog post titled ‘Digital Printing On Glass’
When we think of printing digital images onto different surfaces and materials, we often overlook the process of printing imagery onto glass. To print onto glass, technology has had to be improved down the line and further adapted in order to work on this particular material, as glass does not absorb inks in the same way that paper and fabric do.
The challenging nature of printing anything onto glass meant that until 2007, only two methods had been used. These methods were Silk Screen Printing and Digital UV printing.
Silk Screen Printing
The method of Silk Screen Printing, in which ink is applied directly onto the surface of glass through a woven mesh stencil, was patented by an English man called Samuel Simon. However, this particular technique can be traced as far back as to ancient China during the Song Dynasty.
The technique of an image being transferred from paper onto glass was patented in the 1930’s by Johnson Mattey. Much like Samuel Simon’s method of Screen Printing, Mattey’s method involved using fire to infuse the ink permanently with the glass.
UV Pinning is another method of printing onto glass. This was the first technique of printing on glass that allowed any digital image to be able to be printed directly onto it.
To dry these inks onto the glass, Ultraviolet Rays are used. However, in order for a clean and precise print, the UV light’s wavelengths must be correctly matched to that of the ink’s photo-chemical properties.
The Digital Glass Printer
More recently, the most efficient method of printing onto glass surfaces is by using a digital glass printer. This printer has print heads that jet ceramic ink onto the glass. During this process, the glass remains stationary whilst the flat bed digital printer moves across the surface which paints the image. The ink used by the printer dries almost immediately after the ink touches the surface of the glass.
Ink is only sprayed onto the surface of the glass once, as this is all that is required, even when printing multi-layered and multi coloured images. This method of printing is called Drop Fixation and makes it possible to create double vision images onto the glass.
The double vision technique means that depending on which side the glass is being viewed from, a different view of the same image can be seen, which is similar to a hologram style of effect.