Finishing techniques include cutting and creasing, varnishing, laminating, embossing and foil applications.
Summary: Main finishes available
There are many different finishes that can be added to the final print job, and again is classed as print finishing being a final procedure.
- Lamination – The most common finish is a lamination. This is where a plastic film is heated onto the paper. The finish can either be a gloss, silk or matt lamination.
- UV Varnish – This is a cheaper alternative to lamination, and is a varnish rather than a film, and gives a high gloss finish.
- Spot uv varnish – This is where perhaps pictures or images are picked out in gloss or matt uv.
- Embossing – This is a raised area, perhaps highlighting a logo or picture.
- Foil Blocking – A technique to apply an image to paper or board using metal foil. This technique is normally used for prestigious literature
Printing: letterpress, lithography and gravure
These printing techniques require more expensive equipment, but will be found in commercial graphics manufacturing.
This method was originally done with moveable type. It is a form of relief printing – where the parts to be printed, both type and illustrations, are raised up from the base plate. It is commonly used for small printing jobs such as business cards and stationery. Illustrations for letterpress printing are made by a photographic process. Types of letterpress printing machines are:
- Platen press The paper is pressed against the printing plate by a flat piece of metal called a platen. The plate is inked by rollers as the platen is opened.
- Sheet-fed rotary press These have a curved printing surface and can print single sheets at a high speed.
- Flat sheets are fed between the plate and a pressure roller.
- Flat-cylinder press The printing plate is flat and paper is passed over it by a rotary pressure roller.
Letterpress printing is not often used now, as it is time-consuming to set up the loose type and make the plates, and there is only a limited range of fonts and styles.
Letterpress printing of newspapers. Nowadays flexography or offset-litho presses are used.
This is similar to letterpress printing. It uses a relief image and thin, flexible printing plates made of rubber or photopolymer. The image on the plates is produced by a photographic process, and the inks are quick-drying thin liquids. Flexography can be used to print on materials such as cellophane, polythene and metallic films, so the technique is used for printing plastic shopping bags and packaging for food products. It is also used to print newspapers and paperback books.
This is the most widely used method of printing today, and is equally good for colour work as for black and white printing. The process works on the principle that oil and greasy substances do not mix with water. The plate to be printed is coated with a type of grease, then rinsed, dampened with water and coated with ink. The ink only sticks to the parts of the plate that are not wet with water. The plate is fixed to a cylinder, paper is fed through and the image is transferred onto the paper.
Offset-lithography machines work using the same principle, but the paper does not come into direct contact with the printing plate, as the image is first transferred to a rubber roller. The printing plates for lithography are made by a photographic process. Lithography is used for medium and long printing runs of products such as magazines, posters, packaging and books.
For this process, the image to be printed is made up of small holes sunk into the surface of the printing plate. The cells are filled with ink and the excess is scraped off the surface, then a rubber-covered roller presses paper onto the surface of the plate and into contact with the ink in the cells. The printing plates are usually made from copper and may be produced by engraving or etching. Gravure printing is used for long, high-quality print runs such as magazines, mail-order catalogues, packaging, and printing onto fabric and wallpaper. It is also used for printing postage stamps and decorative plastic laminates, such as kitchen worktops.
Cutting and creasing
Some printed materials will need to be cut after printing, and, if necessary, creased so that they can be folded. This particularly applies to packaging, but also to pop-up cards and books, and press-out shapes for model making.
A die cutter is the commonest cutting machine. The die supports the material being cut and has a hole or a recess into which a punch made of cutting blades fits exactly. The punch and die are fitted into a punching machine, or sometimes a converted letterpress machine. The work to be cut is fitted into the machine and the punch lowered down to cut. For creasing, the same technique is used, but with blunt blades that will crease the product. Cutting can also be done with a CNC cutter.
Die Cutting can be used to produce different shapes on most papers & boards (including thicker display boards). Also most pockets for folders and apertures are achieved using this process
These finishes can provide the ultimate in decorative appeal. They are not limited to gold and silver foils, but extend to an impressive range of pigmented,holographic and security foils.
All of these can be combined with embossed images to produce varying tactile effects – any one of which will enhance the printed message and provide shelf appeal for greetings cards, cartons, magazine covers, brochures etc.
A technique where a metallic foil is applied to a specific area of a printed sheet (such as a logo) to create an eye catching shiny effect. The method uses heat and pressure too apply the foil and the result is a much shinier finish than normal Metallic inks. However, it is more expensive as it requires special tools to be made.
Embossing / debossing
Embossing gives you the opportunity to enhance your print with stunning 3-D effects. Embossing is particularly effective when used in conjunction with our other processes i.e matt lamination and spot U.V with the spot U.V image embossed out of the lamination or foilblocking and embossing… Let your imagination run wild!
Subtly highlights specific areas by adding a 3D effect. Often used with foiling and laminating.
Embossing is the stamping of a design into paper or card to produce a raised effect, whereas blind embossing uses no ink or foil – the design is only visible as a raised area. Debossing, on the other hand, creates a depression rather than an impression.
Thermography adds an exciting new dimension to printed products by producing a raised finish to selected areas, such as a heading or logo, to highlight them. It can also be used as a less expensive alternative to Hot Foil Printing.
Different thermorgraphic powders will produce different finishes.
Popular uses for Thermography include: