Offset varnish has modest gloss attributes and is mainly used as protection for printable materials during their preparation stages, also to prevent ink rub-off on completed printed matter.
To ensure proper technical quality, offset varnish should be used always when the printing ink is dark and its surface is large. Offset varnish is printed in offset sheet printing presses in a manner similar to that used for printing ink.
Dispersion or water varnish ensures a better gloss than offset varnish and does not turn yellow for a longer period.
This varnish dries physically and can be used in printing presses with a separate varnishing device installed.
The most efficient varnishing results are achieved with UV varnish (more or less equal to lamination) as it consists almost completely of solid substances that become polymerised under the UV light influence.
UV varnish is applied with a separate varnishing machine or in a screen printing press and this varnish can be applied either on the image alone or the whole sheet surface.
Lamination is the process of gluing onto the paper surface of a thin acetate or polypropylene film. Such film can have a glossy or matte surface.
Press lamination and special lamination options exist as well. Press lamination comprises various patterns pressed onto the film (for instance, patterns reminiscent of fabric texture).
Lamination cannot be applied to only some part of the printed surface – it must always cover the whole sheet.
Varnishing and lamination restrictions
The success of varnishing and lamination always depends on the quality properties of the printing base. If the surface of the base material is smooth and dense, the end result will be excellent. Porous and uneven paper types are not suitable for varnishing and lamination.
It should also be remembered that UV varnishing and lamination cannot be applied to paper types of under 100 g/m2. There are no restrictions for coated hard paper.
UV-varnishing machine Steinmann Colibri Junior has been in operation since the beginning of 2008. The purchase of this workbench allows us now to fully control the whole printed material production process and its quality.