UV Printing Technology
First of all, a brief clarification: SPOT UV refers exclusively to UV printing. There are other ways to achieve the same effect, but more on that later.
So, UV printing uses UV inks, which polymerise when exposed to ultraviolet light and dry instantly. UV technology significantly expands the range of materials that can be used for printing. In addition to paper and cardboard, it is possible to print on various polymer films, plastic, laminated and metallised materials, and even metal. When selecting a material for printing, it is important to remember that on very porous (especially uncoated) paper or cardboard, UV ink may be absorbed and remain unpolymerised; therefore, pre-coating with a primer is recommended for such materials. Special UV inks must be used for printing on non-absorbent materials. Also, some polymeric materials contain plasticisers, which may hinder the polymerisation of the ink or cause it to soften.
What materials can UV printing be used on?
Below is a table showing the adhesion of UV inks on various materials
| Material | Adhesion Level |
|---|---|
| Coated Paper | 100 |
| Coated Cardboard | 100 |
| Polyethylene | 100 |
| Polyester | 100 |
| Polystyrene | 75 |
| Thermal Coated Paper | 100 |
| Synthetic Paper | 80 |
| PVC | 100 |
| Polypropylene | 75 |
| Acetate | 50 |
| PET | 50 |
Adhesion Scale:
- 100 - excellent adhesion
- 75–80 - normal adhesion, but pre-testing and surface coating are recommended
- 50 - acceptable adhesion, but pre-testing and surface coating are recommended
What is Spot UV
Spot UV is a coating applied to specific areas of the printed surface. The term "spot" refers to its selective application; depending on the objectives, we choose which specific design elements to coat: the headline, logo, illustration or pattern. Spot UV Effect creates a striking contrast between the glossy-coated areas and the surrounding surface. It looks particularly good on a matt or laminated background, where the difference in texture and gloss is most noticeable.
Raised Spot UV
This is just the beginning of exploring the possibilities of UV printing technology.
In addition to highlighting a specific area of the design using varnish, there is a technique for creating an embossed effect. This is known as the raised spot UV effect.
The unique feature of this technology is that the varnish can be layered to create raised textures on the printed surface. The simplest example is an element that appears raised when viewed and even when touched. A more complex example is imitating the texture of genuine leather or applying a wood grain texture. In addition, varnish can be used to create a brushstroke effect to imitate oil paintings.
Raised Spot UV is also known as 3D UV or sculpted UV.
Scodix vs Spot UV
So what is the difference? In reality, there is no difference, as Scodix is the brand name of a company that manufactures equipment specifically designed to create Spot UV varnish, foil and embossing effects.
What is Scodix?
Scodix is digital finishing technology is based on inkjet deposition of UV-curable PolySense polymers applied selectively to printed sheets. The system delivers precise control of varnish placement and volume, enabling flat gloss, selective coating, or raised tactile effects. It supports multiple substrates, including offset, HP Indigo, and toner-based digital prints, using optimised polymer formulations to ensure reliable adhesion and consistent surface quality.
Specifications: Maximum gloss level up to 99 GU; varnish thickness range from near-zero tactile layer to 250 µm; deposition accuracy within ±1%; three-stage curing process with LED-UV pre-cure, intermediate flow control, and final UV polymerisation; compatibility with foiling through controlled partial curing.
How Print Spot UV Effect
How Standard UV Flatbed Printer Workflow Operates
When working with a UV flatbed printer, the process usually runs in stages. First, the base artwork is printed using standard UV inks. Once cured under ultraviolet light, the sheet is reloaded or repositioned. Then a second pass applies the clear varnish layer exactly where the Spot UV effect is required. Sounds simple, but precision matters. Alignment must be spot on, otherwise the gloss layer shifts and ruins the finish. Operators often compare it to lining up a die cutting tool, where even a small misalignment becomes obvious on a finished label.
Material Considerations for Reliable Results
Not all substrates behave the same. Coated stocks, synthetic films, and rigid boards respond well to uv print, while porous materials may require priming. In label and sticker production, consistency across runs is critical, especially in industrial volumes. Surface tension, ink adhesion, and curing intensity all influence how clean and raised the final effect appears.
Single Pass Spot UV with Quantumjet Elite UV
The Quantumjet Elite UV changes the workflow completely. Instead of running multiple passes, this system delivers both colour and Spot UV in one continuous process. That means no reloading, no registration issues, and a much faster turnaround. For commercial packaging jobs, especially short to medium runs, this approach saves time and reduces waste. The machine applies varying thickness of clear coating in one go, allowing both subtle gloss and raised tactile finishes within the same print cycle.
