If you’ve ever wondered how intricate, full-colour designs get printed onto glass bottles, or how vehicle graphics and window decals are produced with such vibrant colours, the answer is usually UV printing.
Also known as Ultraviolet Printing, it's a digital print technology that uses specialised UV lights to cure (dry) ink almost instantly as it hits the material.
How Does UV Printing Work?
Traditional solvent inks dry by evaporating into the air. UV ink is completely different. The printer lays down the ink, and a high-intensity UV LED light immediately passes over it.
This triggers a chemical reaction called polymerisation. The ink doesn't just dry; it hardens instantly into a durable layer on top of the substrate. Because the wet ink dots don't have a chance to spread out before drying, this results in incredible photographic detail.
The Two Main Types of UV Printers
While the curing technology is the same, UV printers generally come in two distinct formats depending on what you need to produce:
1. UV Flatbed Printers
These are designed for printing directly onto rigid substrates and objects. The material sits flat on a stationary bed while the printhead moves over it.
- Best for: Perspex, wood, glass, dibond, phone cases, golf balls, promotional merchandise, and thick rigid signage.
2. UV Roll-to-Roll (Roll-Fed) Printers
Roll-fed UV printers are revolutionising the sign and graphics industry. Instead of rigid boards, these machines print onto flexible media fed from a roll, combining the versatility of traditional eco-solvent printers with the rapid-curing power of UV technology.
- Best for: Self-adhesive vinyl, window graphics, backlit films, banners, wallpapers, labels, and vehicle decals.
Why Roll-Fed UV is Changing the Game
If you are producing large-scale graphics, investing in a roll-to-roll UV system like the Mimaki UCJV330 or the Roland TrueVIS MG/LG series offers massive workflow advantages:
- Zero Degassing Time: Solvent prints require 24 to 48 hours of "degassing" before they can be safely laminated or cut. UV prints cure instantly, meaning you can print, laminate, and install a job on the exact same day.
- High-Opacity White Ink: Roll-fed UV printers excel at printing incredibly dense white ink. This is crucial for creating vibrant window graphics on clear vinyl or printing vivid colours onto dark substrates.
- Multi-Layer Printing: Advanced UV roll-to-roll machines can print multiple layers simultaneously (e.g., Colour-White-Colour). This allows you to produce stunning day/night backlit graphics that look perfect whether the lightbox is illuminated or switched off.
- Texture and Varnish Effects: By building up layers of clear gloss ink, roll-fed UV printers can add raised textures or spot-varnish effects to premium labels.
Not sure which UV technology fits your business?
Whether you need a flatbed for promotional goods or a high-speed roll-to-roll system for same-day window graphics, our tech team can help. Visit our Preston, Lancashire HQ for a live demonstration, or send us your trickiest substrate for a free print test.
Book a Demo or Print TestCommon Questions About UV Printing
Will a UV printed material glow under UV light?
No. Even though an ultraviolet light is used to cure the ink during the printing process, the finished print will not glow in the dark under a UV blacklight.
Are UV prints fluorescent?
No, standard UV inks are not fluorescent. They produce highly accurate, standard CMYK colours, often with a much wider colour gamut than traditional inks. That said, Mimaki's lasted Flatbed Printers, the UJF200 and JFX220 do introduce true flourescent Pink and Yellow inks, which can be introduced into the configuration.
Explore Our UV Printer Range
From compact flatbeds to 64-inch roll-to-roll powerhouses, check out our top-selling UV machines below.
UV Flatbed Printers
UV Roll to Roll Printers
Let’s get technical
UV Printing, otherwise know as Ultra Violet Printing is a printing technique that uses special UV curing ink that allows the ink to be printed onto a large range of materials or ‘substrates’. The printer will place the ink on the material and a specifically design UV light, acting as a catalyst, will follow behind, drying (or curing) the ink so that it drys hard instantly. This reaction causes something called polymerisation to occur. The UV ink curing process was originally designed to rapidly dry gel nail-polish during ladies manicures. It quickly became apparent that this quick drying print technology could be very useful in more commercial and industrial applications such as within the sign and print industry.
The UV ink curing process was originally designed to rapidly dry gel nail-polish during ladies manicures
In the ink, you will find small polymers and monomers. These are very light molecules that fuse together to form polymers. The hardening and drying of the Ink happens so rapidly that the wet ink dots do not have a chance to spread out and expand. This results in much finer detail/ higher resolution than other types of printing technologies. If a super-high resolution isn’t a good enough reason to give UV printing a try, UV inks have even more benefits. They are fade and weather resistant and the process of curing the inks is also better for the environment than solvent printing as they give off fewer VOC’s and odours! Win-win! I hear you say.
The UV light, heat and warping
If you are using non-LED bulbs, there is a lot of heat created during the printing process due the the high intensity of the ultraviolet light. When you heat a material or substrate on one side it can become prone to warping due to one side being hotter than the other. (Thicker materials are generally more prone to this). This warping and bending is overcome by clamping down the material so that it is unable to lift up. The UV flatbed printer will also have suction holes in the print bed that will create a vacuum which helps the material from lifting from the print bed.
Avoid the heat with a UV LED light
All UV printers, both flatbed and roll to roll that Granthams sell use LED ultra violet bulbs. Using an LED bulb makes the curing process a heat free affair. This eliminates the warping and bending issues described above and makes them energy efficient and environmentally friendly at the same time.
So why is UV print so popular?
UV printing technology contains some of the most up to date printing technology in the world and can be used on a huge range of materials. They are also low odour and great for the environment.
What materials/substrates can you print on with a UV printer?
UV printers can be used on a huge variety of materials/substrates. Some of these include Perspex, plastics, wood, glass, tiles, metals, paper, cardboard, Dibond and Correx. In terms of practical applications, think glass bottles, mobile phone cases, golf balls, pens & pencils, key rings, plastic cards ie. membership cards. The UV ink sits just above the surface of the substrate and sticks to it’ face. Darker colours can feel slightly higher on the surface due to the amount of ink needed to cover and generally speaking the finished print can feel slightly rough.
Some common questions answered regarding UV printers
Will a UV printed material glow under UV light? After all, a Ultraviolet light was used in the printing process. No. You’re finished print will not glow under ultra violet light. The fact that an ultra violet light was used in the curing/drying process does not mean the finished print will glow in the dark.
Does a UV print mean it is fluorescent? Rest assured, you’re finished UV prints will not be fluorescent.
What are the benefits of UV printing?
- Fade and weather resistant
- High photographic detail due to the high resolution
- Flatbed and roll to roll UV printers are available so you can print onto rolls or rigid substrates.
- There is no need to laminate a UV printed surface
- Your prints will be scratch resistant
- The finished print will generally have a more durable surface than a solvent printer
- UV printers are environmentally friendly when compared to other types of printer.
Granthams sell a wide range of UV printers including flatbed UV printers from Mimaki and roll fed UV printers from Mimaki and Roland. In this article I will explain exactly what UV printing is, what applications it can be used for and why it is so popular amongst sign makers and print shops all over the world.
I hope I have provided you with some value in this article. If you are interested in purchasing a UV printer, please feel free to view our range of UV flatbed printers and UV Roll to roll printer below. Or contact us for more information.