THE PROPERTIES OF OFFSET INKS

The article gives an overview of the properties of offset printing inks which are
leading on the market of printing services. The explanation for this is the availability of a wide
range of automatic printing presses of the leading manufacturers and the use of various
printing materials and printing inks depending on the intended use of the product. The
predominant advantages of this printing method include high graphic accuracy in the
reproduction of small line breaks and colour reproduction. During printing, the quality of the
reproduction depends on many factors, including the properties and characteristics of the
printing inks used, which differ from each other in terms of composition and the quantity of the
basic components. The composition and percentage of the basic components of inks differ
depending on the printing method, type of printing equipment, dampening system, optical
characteristics, fixation method and characteristics of the print material. For printing on
absorbent substrates, less viscous inks should be used in comparison to printing on non-absorbent
substrates. The higher the viscosity, the lower the tendency of the ink to spread over the print
substrate, the higher the print resolution and the lower the dot gain. It follows from this that
before selecting and using an ink it is necessary to know the type of printed matter and its quality,
colour tone, brightness, colour saturation, etc. In tri-colour, printing it is important to ensure
sufficient transparency of the ink; otherwise, the desired colours cannot be achieved in the print.
The tack of the inks must be adjusted because they will be applied one after the other; the
viscosity of the ink must also be adjusted to the characteristics of the print substrate in order to
compensate for dot gain and to ensure better print quality. Conclusions are drawn on the
influence of the optical and printing properties of the inks on the colour reproduction of the print.