What paper types are suitable for lamination? Can you varnish selected images? How many pages can you staple? Is there a finish that protects the printed product? Are folding and scoring the same thing? Can you laminate uncoated paper? Why are printed products usually varnished? Why is the grain direction of the paper important when folding?
Varnishing is the most common surface treatment and consists of putting a glossy surface on a printed product. Varnish is a liquid just like ordinary printing ink. Varnish can be applied selectively to a printed sheet (partial varnishing) or it can cover all of the sheet. It may be applied in the offset press, via a regular inking unit or a special unit for varnish, or in a dedicated varnishing machine.
Varnishing is used mainly for special visual effects, or to make faster off-press processing possible. It can also give extra protection against dirt and wear.There are three kinds of varnish: oil-based varnish, dispersion varnish, and UV varnish.
Oil-based varnish can be applied directly to the print in the offset press. Oil-based varnish is mainly used to create a glossy finish, to protect the print against the effects of postpress processing, and to avoid toning (when the printing ink’s pigments color nonprinting areas after the ink has dried). When you want to protect the printed product, you usually choose a matte varnish, which is invisible. If you want to create a glossy effect, you get a better result with a separate varnishing run once the ink has dried.
Varnishing with dispersion varnish, which is water-based, can be done directly in the offset press and can give a higher gloss than oilprint varnish. It can also yield a high gloss when applied during the same print run as the ink (that is, printed wet-on-wet). Food packaging is a typical use of this technology since dispersion varnish is totally odor-free.
UV varnishing is another common method, in which the varnish is cured with ultraviolet light. UV varnish can be applied in a thicker layer than the other methods and thus provides a higher gloss and a harder surface.
With all types—oilprint, dispersion, and UV—varnish can be applied selectively to certain parts of the image, such as over images and logotypes. This partial varnishing is used for aesthetic effect. If you varnish only the images in a printed product, it can create an impression of higher image quality. Keep in mind, though, that fingerprints show easily on glossy printed products.To obtain the best results with varnishing, coated paper is preferred. Varnished sheets should be creased before they are folded to avoid the formation of cracks on the surface hardened by the varnish.
Lamination increases protection against dirt, humidity, and wear and tear. Lamination is the process of coating a printed page with a protective plastic foil. The method is also used for aesthetic reasons. There is a variety of laminates, including glossy, matte, embossed, and textured.
Multi – level Emboss and Debossing
Embossing is the raising or pushing a desired image or shape up above paper. Debossing is the pressing or pushing the image below the level of paper. both achieved by machinery.
When you want to create a relief effect in a printed product, you can make use of embossing. Embossing differs from other surface finishes since it is a physical reshaping of the paper. Embossing can cause the print to stand out (positive embossing) or to sink down (negative embossing). There is also a variation called sculpted embossing, where the embossing can have several levels. Embossing is normally done in regular book printing presses.
In embossing, a lower die with raised surfaces corresponding to the embossed shape is pressed into the paper against a resistant surface, the upper die, that has an etching that is the exact opposite of the lower die. The lower die is made of 7 mm thick magnesium, which has been etched to a 3 mm height difference. The upper die is made from a special plastic material. Most paper can be embossed, but to avoid the formation of cracks along the edges, long-fibered paper is preferred.
Foil embossing is a form of embossing where you apply gilding or shiny ink during the actual embossing. It is done in special printing presses. The lower die is heated and the foil applied to the paper at the same time as it is embossed.
Relief type is another finish that creates a relief in the printed product, but without embossing the paper. You print what will be in relief with special ink. The ink is then heated and rises, creating a relief. This method is perhaps most common on business cards.
Score, Cut, Crease and Die Cutting
Machinery cutting of desired shapes and images of paper, boards, sitcker and other packaging material.
Hot & Cold Foil Stamping
Another surface finish is foiling, which is done for purely aesthetic reasons. You can create metallic surfaces, metallic colors, or extremely saturated finishes. The coating is thick and covers all, and so gives the product a unique surface feel. The ink or the metal is transferred from the foil to the printed matter with the aid of a warm plate. The affixture a gold/silver/metallic foil layer to a mterial by a heating or cooling process.
Silk screen printing is a stencil method of print making where a design is imposed on screen of polyester or mesh, with blank areas coated with an impermeable substance and ink is forced through the mesh onto the printing surface.