Cold foil transfer

The cold foil transfer is one of the print finishes that have been developed in the recent past. By transmitting a metallized lacquer layer which is peeled from a carrier film and optionally subsequent overprinting different metallic effects can be achieved.

Technical Background

Cold foil finishing is realized with two additional printing units in an offset printing machine. In the first printing mechanism, a special adhesive is applied to the substrate using a standard printing form. Since the characteristics of offset printing come to fruition, fine grid elements and fine-line thick are transferable.

A second printing unit is equipped with a film transfer device. The film is passed from the unwind station into the printing gap between the blanket cylinder and impression cylinder and brought into contact with the substrate.

The film consists of several layers, which are located on a carrier film. Color agents are an aluminum layer and a protective lacquer layer, the coloring affects the color impression. By adhesion of an adhesive layer with the printed adhesive layer, the transfer layers remain adhered to the substrate. The carrier film is then rewound. After the cold foil transfer overprinting is inline possible with conventional printing inks as well as UV and hybrid inks to produce different metallic shades.

Effect

The optical effect of the cold films is similar to the hot-stamping foils. Iridescent and reflective surfaces, such as metal, water or glass, can be implemented realistically. On the basis of only a standard silver film can be formed by overprinting almost any desired color. A haptic effect remains off, however, since no deformation or tactile surface change takes place.

Application Possibilities

Cold foil in the manufacture of various printing products are used, such as label printing, to high-quality packaging or commercial printing. Also for the cover design of facsimiles, represent the cold foil is an interesting type of finishing. Effect films or film combinations can also in the field of security printing applications, see (e.g. fuse against counterfeit products). Conceivable is also a use in security printing.

Limitations

For the cold foil finishing less site-specific masses of the printing plays a role as his surface features. Recycled paper, structural and uncoated natural paper are less suitable. The film adhesion may be limited, the printed image may appear restless. Very absorbent printing substrates are also not recommended. Therefore, in contrast to hot foil stamping temperature sensitivity does not matter.

For the subject, there are virtually no restrictions. Both solid areas as well as very fine and delicate font (from 5 pt) and line elements (from 0.25 pt) can be very well realized. However, there is a danger that gloss is limited because of the contrast and hence the readability and recognizability at very fine elements. Even when overprinting of the foil with fine lines and writings, the contrast reduction is taken into account, especially in bright colors. From certain angles it can no longer be perceived. For this reason, the film should already be applied in the creative construction phase as a special color and the subsequent action to be considered.

Regarding the resistance must be kept in mind that cold foils are sensitive to mechanical stress. Therefore, an additional surface protection as an aqueous or UV varnish or a foil lamination is recommended.

Costs

The cost depends on the size of the motive to be refined. The method is viable only with full utilization of the format. Cost advantage brings the fact that the processing can be done inline in the press and in comparison to other types of refinement No special tools must be produced. However, a prerequisite for the cold foil transfer are two additional printing and foil transfer station.

Sources and additional literature

[1] Beckmann,

Till; Morlok, Franziska: Extra: Enzyklopädie der experimentellen

Druckveredelung; Birkhäuser Verlag, 2009

[2] Webseite von WDS Pertermann

[3]   Webseite Printperfection

  

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