This page explains some of the commonly used terms in the field of UV curing technology. If you would like any of this information explained in further detail, please don’t hesitate to contact us

Arc lamp

A sealed quartz tube filled with a gas which separates two electrodes. An electric arc is struck between the two electrodes which ionises the gas and generates high intensity light (and UV) radiation.


A chemical reaction initiated by the exposure of a photoinitiator compound to UV radiation. When this takes place in a liquid ink or coating, it transforms to a solid state as a cross-linked polymer network.

Doped lamp

A UV lamp containing and additive, such as iron or gallium, to alter the spectral output of the lamp to suit different types of ink or coating. Compared with mercury lamps, doped lamps do not start as easily or last as long, however they are not required for most printing and coating applications.

Electric arc

An electric current passing through a normally non-conductive medium such as a gas, causing an electrical breakdown of the gas and an ongoing plasma discharge.


The band of the electromagnetic spectrum ranging from 700 nm to 1 mm.


Abbreviation of infrared.

IR drying

In the context of printing and coating, this refers to the use of infrared radiation to excite and evaporate the water or solvent molecules in conventional inks (typically about 40% of the volume), leaving a solid pigment residue on the substrate.


The part of the UV system fitted to the printing or coating machine that houses the UV lamp, reflector and shutter mechanism.


A curved, polished surface inside the lamphead located behind the UV lamp to reflect and focus the UV light back onto the substrate for maximum curing efficiency.


A mechanical shield that closes over the UV lamp when the printing or coating machine is stopped. Arc UV lamps cannot be restarted for a while after they are switched off, so the lamp power is reduced and shutters are instead used to prevent UV and heat radiation from reaching the substrate.

Spectral output

This refers to the range of electromagnetic radiation wavelengths emitted by the UV lamp. UV ink and UV coatings are tuned to react to a particular wavelength of UV light.


The band of the electromagnetic radiation spectrum ranging from 10 nm to 400 nm.


Abbreviation of ultraviolet.

UV ink

An ink which solidifies of ‘cures’ on exposure to UV radiation. Unlike conventional inks, UV inks do not require IR drying, as they do not contain any solvents.

UV lamp

The source of UV radiation used in UV curing systems. For most printing and coating applications, medium-pressure mercury arc lamps are used.

UV light

The region of the electromagnetic spectrum in the ultraviolet range.

UV printing

Printing with UV ink as opposed to conventional solvent- or water-based inks.

UV ray

A wave of electromagnetic radiation in the ultraviolet range.

UV varnish

A clear coating applied to printed material and cured using UV light to create a glossy finish. UV varnishing is also used to finish digitally printed images to improve appearance and ink adhesion to the substrate.