Cold foil finishing is a complex process in which all components, i.e. the foil, paper, adhesive, inks and lacquer, need to be well matched to one another. The various process steps such as print preparation, application of the foil, overprinting and further processing need to be planned precisely. KURZ recommends carefully testing the interaction of the materials and processes before commencing the production print run.
Glossy photo printing materials gives the best results. For more details see:
Sheet-fed offset printing Photo printing materials
Web-fed offset printing stock and label materials
Cold foil finishing can often produce surprising effects. The effect of the applied foil can only be visualized to a limited extent on a monitor. No proofs are produced either. This makes it especially difficult to predict the interplay of the foil and color print. It is therefore essential to include test printing in the planning. This is best done by producing several, if necessary, smaller test prints with varying cold foils and inks in order to select the best foil design.
It is advisable to always use lacquer to protect the decorated, high-quality print product. High-gloss lacquers can accentuate the sheen of metallized areas to great effect. Commercially available dispersion or UV lacquers are suitable for use with cold foiling. Some preliminary testing should be performed to verify that a particular printing lacquer is suitable for the specific application. The total ink applied should not exceed 340%.
For overprinted cold foils, a drying time of one to two days should be factored in. This applies to the oxidatively drying inks used to overprint foils in sheet-fed offset printing. No drying time is required, however, when UV curing inks are used for cold foil decoration.
All print products finished with cold foil are, principally speaking, foldable and creasable. The further processability does, however, depend on the substrate and the grammage. Here too it is advisable to perform some preliminary testing of the foldability and creasability.