Print finishes

With the help of print enhancements, printed products can appear higher quality and more exclusive. They also protect the products from scratches, for example. Due to technical progress, there are now a large number of possible print finishes. In the print24 blog article you can find out what options are available, how the finishes are implemented and what advantages or disadvantages they bring with them!

What are print refinements?

With print refinements, the surface of print media is changed. This is done either inline, i.e. in the printing press, or in a subsequent process. Print refinements produce various haptic, optical or structural effects, and the quality of the print product is also enhanced. Depending on which process is used for print finishing, extraordinary effects can be achieved through the coatings.

In addition to these aspects, print refinements, for example through the use of a special coating, can protect print products from various external influences. For example, they prevent damage caused by scratches, abrasion, tears in the paper, dirt and water stains or swelling due to moisture penetration, which is essential for packaging in particular.

Due to the way print finishes work, they are particularly popular for advertising purposes, in marketing and in the packaging industry. At the same time, they are also suitable in the private sector for wedding, confirmation or birthday invitations, for example, as well as many other special occasions. The print products can be staged as powerfully or discreetly as desired.

Types of print finishes

Nowadays, print refinements exist in many different processes. These serve to enhance the quality, appearance or feel of printed products. In the following, you will find out which finishing options exist.

Varnishes for print refinement

UV coatings or dispersion coatings, i.e. water-based coatings, are often used in book production because they either form a protective layer over the entire surface or can also be used partially for contours. There are also relief, scented and drip-off varnishes.

Dispersion varnish is a printing varnish. It consists of water-based components that are applied to the paper after printing and evaporate or are whisked away. Dispersion varnish takes only a short time to dry, and it dries even faster when heat is applied. It is usually applied in a small layer thickness, giving the printed product a matt or glossy appearance, depending on the type of coating used. It also helps to improve the paper's properties and increases rub resistance, which means that the ink does not rub off as much. Alternatively, dispersion varnish can also be printed in inline production.

Dispersion varnish contains polymer dispersions, hydrosols, synthetic resins, film-binding aids, wax dispersions and wetting agents as well as defoamers. While the water evaporates after the varnish is applied, the water-soluble resins stick together - creating a smooth surface. Dispersion varnish is an uncomplicated option for print finishing because it is easy to apply and also dries quickly. It forms a protective layer that not only protects the printed product from abrasion but also from water penetration. Furthermore, it does not become yellow and does not stain overlying printed sheets. Since the dispersion coating also remains elastic on the printed product, it can be further processed, for example, in grooves, slots or foil embossing. It proves disadvantageous if the print is to be subsequently labelled, reprinted or stamped, as the ink smears and dries only slowly.

UV varnish is also called UV spot varnish or partial UV varnish. This can be used to achieve high-gloss effects. These are created by alternating coated and uncoated areas on the printed product and at the same time create a great haptic effect. UV coating can be applied in matt or gloss and is made from polymerisable binders. Furthermore, it dries in just a few seconds, but only with the help of special UV drying systems. Since high temperatures are not necessary, even heat-sensitive substrates can be finished with UV coating. Print finishing with UV varnish produces great optical and haptic effects, while at the same time protecting the printed product. They are preferably used as spot varnishing or partial varnishing for special design elements.

In contrast to dispersion varnish, UV varnish consists entirely of solid particles, and no water or solvents are used. This makes the use of UV varnish more environmentally friendly. The coating is applied with the help of a roller, which applies the solid synthetic resin particles to the print product as a film. The subsequent UV exposure causes the particles to bond, resulting in a film that covers the entire surface. The cross-linking also allows thick layers of varnish to be applied, which accordingly achieves a great effect. Thus print finishes with UV coating appear even glossier or more matt. The protective layer also results in a pronounced abrasion resistance and stability, which is particularly in demand for flyers and postcards. The printed products are hard-wearing, abrasion-resistant and retain their value.

Relief varnish is a special type of UV varnish. This can be transparent or pigmented in colour and can highlight lettering and motifs three-dimensionally (3D coating). The substrate is not deformed in the process. It is also available in matt or gloss. Relief varnish is also available as textured, contour, water drop or Braille varnish. Within the screen printing process, it can be applied in very high layers, whereby large layer thicknesses can be achieved after curing with UV light. Relief varnish produces the most striking effect when it is used for linear or rough motifs. Glossy lettering looks particularly impressive on a matt substrate. Relief varnish is popular for highlighting headlines and book titles as well as on brochure covers. It works very well on coated and smooth paper, as well as on foils and laminates. However, the more filigree the relief varnish is applied, the lower the layer thicknesses that are only possible. However, they are still clearly visible. Likewise, very large-area motifs can appear uneven with this print finish, with the varnish also sinking into the centre. It should also be noted that transparent relief varnish changes colours that lie beneath it. It might bleed varnish onto other sheets if printed products finished with relief varnish are stored in a stack.

Scented varnish can also be used for print refinement. This is an effect of varnish enriched with microencapsulated aromatic substances. These are added via a chemical-physical process, and stabilisers are also added. It is only applied as the last layer on the printed product. If pressure or friction is applied, or if the label is opened, the capsules burst open and release the fragrance. However, since not all of them burst open at once, the fragrance effect can last for up to 10 years. With scented coatings, there is a wide choice between different fragrances.

Print refinements with scented coatings can be applied partially or over the entire surface in flexo, gravure, screen and offset printing processes. However, the web offset, screen and sheet-fed printing processes are predestined. With the screen printing process, high layers of varnish can be achieved so that the scent is emitted more intensively.

In print refinements with drip-off varnish, two chemically different varnishes are printed. First, matt oil-based inks are applied to the areas that are to have a matt effect. Then a high-gloss water-based thermal dispersion varnish is printed on the entire surface using the wet-on-wet process. Both the different surface tensions that occur and the repulsion between oil and water create the drip-off effect. As a result, matt surfaces appear even more matt, while glossy surfaces stand out more. This type of print finishing is thus based on reflection differences between two types of coating, which makes it possible to achieve excellent contrasts. The process is popular for finishing annual reports, catalogues for high-priced products or image brochures.

In addition to the coatings mentioned, there are also sand, soft-touch, Iriodin, glitter, silver, gold and thermal coatings that can be used for print refinement.

Embossing for print refinement

Another type of print refinement is embossing. In this process, the surface of the material is transformed with the help of temperature, pressure and time. Embossing of print products can be done partially as well as over a wide area. This is why it is also known as embossed foil printing. Basically, the different types of embossing can be carried out in an uncomplicated and cost-effective way. Two steel rollers press a motif into the embossing material. The motif is engraved into one of the two rollers beforehand, which is then heated so that it can be pressed into the substrate. At the same time, a heat-resistant and soft material coats the surface of the second roller. The embossing tool can press itself into this roller so that the three-dimensional image is created at the end. Both rollers are pressed together while the substrate is in their centre. It is important not to apply too much pressure and heat so as not to tear or burn the substrate.

Print finishing by embossing can be done in different ways: Blind embossing, hot foil stamping, relief embossing or steel engraving.

In blind embossing as a print refinement, a paper is embossed high or low. For this purpose, an embossing die is used which deforms the paper by pressure (and in some cases temperature). The effect achieved by blind embossing is created by the interplay of light and shadow, which emphasises the print finish. The prerequisite for blind embossing is paper fibres of sufficient length, which can be deformed accordingly.

In hot foil stamping, a coloured foil is embossed onto the printed object under pressure and heat between 80 and 200 °C. A special embossing die is used for this. The foil can be gold, silver, aluminium, metallic or copper, for example, which gives the print medium a particularly luxurious appearance. This is why hot foil stamping is popular as a print finish for covers, book covers, magazines, brochures and business cards. The resulting 3D effect can be felt, and there is also an optical effect due to different incidences of light and reflection. Hot foil stamping is mainly used in the sheet-fed printing process, as the production of the embossing clichés is more time-consuming.

If special areas of a printed object are to be highlighted by a 3D effect, relief embossing is used. Both the embossing foil and the substrate are raised or deformed three-dimensionally. Attractive light-shadow effects are created, which enhance the gloss of the foil and, in combination with this, the changed feel of the printed product leads to an increase in its exclusivity. Relief embossing can be done either in a single step or in two steps. In the first method with relief engraving, the forming and the foil transfer are carried out simultaneously. In this case, the relief engraving of the embossing tool requires more effort. On the other hand, this method saves time and the foil and the embossing are transferred accurately. With two-stage relief embossing, the embossing foil is transferred first and then the reliefs are inserted using blind embossing. However, this process is cost-intensive and is therefore used less frequently.

One of the most noble embossing processes is steel engraving, which is produced by intaglio printing. This print refinement produces a contour-sharp print image, and at the same time the motif is raised on the front and can therefore be felt. The reverse side of the printed product is also embossed, with extremely fine lines and hatching. The printing areas are deeper in this type of print finishing and are enriched with a form of varnish ink. This is followed by pressing the paper into the ink recess. In this way, finer lines are achieved than with hot foil stamping.

Other print refinement methods: from flocking to lamination

In addition to the above-mentioned print finishing options, there are also a few other special processes.

Flocking as a print refinement can be felt with the fingertips. A wide variety of fibres of different strengths and lengths can be applied to the coated surface of the print product with adhesive. This creates soft, plush, velvety or even brush-like surfaces. Due to the high-quality adhesive formulations used, the flocking lasts for a long time. The individual fibres are available in different colour shades, whereby multi-coloured flocking involves a great deal of work and correspondingly high costs. It is also not possible to create fine lines with flocking. As an alternative to the glueing process, flocking can also be applied by partial flock printing.

With the help of lenticular printing, 3D effects, wiggle images, zooms, morphing or animations can be achieved, which are often accompanied by optical illusions. In this process, exact image variations mounted in strips over-respectively into each other are combined with a lenticular sheet glued on top. The effects occur by viewing the printed object from different angles. It is possible to mount up to 34 image variants, which are usually computer-generated, one inside the other.

Another possibility of print refinement is the cold foil transfer. In this process, a foil is stuck onto a print substrate to achieve an initial finish. The film can be printed inline, i.e. directly after application in the press. Since, in contrast to hot foil stamping, no high temperatures are required here, this is also referred to as cold foil finishing.

In foil lamination as a print refinement, a foil with adhesive is applied to the entire surface of the printed product after printing. The foils used are very fine and thin and are made of polypropylene, polyester, PVC or acetate. The film lamination can be matt, glossy or soft-touch. It is also called film lamination or cellophaning. The process can increase the stability of the printed product and also protect it from moisture or mechanical influences and dirt.

Laminating also provides improved stability. In this process, a thin, usually film-like layer is bonded to a carrier material by using adhesive. This is done on both sides of the print object so that it is completely enclosed by the protective layer.

Laser cutting or laser engraving, on the other hand, can be used to create extremely fine cut-outs and separations from paper or cardboard. This is done by laser radiation to produce graphics, logos or other details. The motifs have an extremely refined effect.