ACADEMY

PRINTING - THE METHODS

Academy »  Printing »  Printing - the methods

Digital printing

Digital printing

Digital printing - the printer

Today, digital printing has increasingly been used for small series (the so-called low-edition printing). Printers range from simple printers and copiers up to professional printing machines worth many millions of crowns. These machines utilize the CMYK color environment. The printing ink used is mostly powder (toner), yet there are exceptions. In order to prepare them for running, you do not need any prepress editing, nor do you need printing plates (metal masters), neither any prestart preparation. Compared with offset printing, digital printing is, in itself, more expensive. This is why it is not appropriate to use this technology for mass-printed leaflets, for example. By contrast, digital printing of lower-edition materials, and also materials whose contents vary with each print-out, will pay off. This digital technology makes it possible, among other things, to print books with inscriptions or annual reports intended straight for a specific user.

Even though digital printing is recommended for lower editions, it is more and more often used in mass-printing of personalized letters or products´ manuals. For, in doing so, an annual saving worth hundreds of thousands, if not millions, of crowns can be realized, provided that only those parts of manuals that their users can really use are printed. German-speaking users, for instance, are not interested in an instruction printed in Turkish or Italian, and if ways of distribution on these disparate markets can be fixed in terms of the logistics, the aforementioned savings can be achieved very quickly.

The quality of printing, selection and format of printed materials, the price as conditioned by the number of copies – these are all criteria we are going to consider while choosing a particular technology to meet individual company needs.

The quality of printing

Generally, as compared with the offset technology, digital printing´s quality is lower. In recent years, however, this technology has made enormous advancement, so most printed materials can comfortably suit their purposes – the quality does not act as an interfering element here any longer. In classical books, for example, a regular user is unable to distinguish whether a book has been printed with digital or offset technology. On the other hand, printing a memorial volume of photographs on glossy paper for exhibition purposes is certainly not a job suitable for a digital printer.

Selection of materials for printing

The choice of decoration printing materials is limited to materials that suit the digital printing technology. Unlike the offset, here the fixing of ink to the base is done by means of the joint effect of temperature and pressure. The temperature inside the fixing unit ranges around 200 ˚C, a temperature at which certain paper component parts with a potentially harmful effect on the printing machine are released. Most frequently they are free ketones – waxes. Nevertheless, thanks to a growing demand for these products, the choice of suitable materials has been expanding very fast.

Format of printed materials

The printing sheet here is smaller than the offset one, mostly it is an A3++ (305×457 mm, resp. 320×450 mm) format paper. The format is limited due to technological reasons, viewing the limitations imposed by the need to maintain the color register. With regard to the fact that an absolute majority of materials are in formats smaller than A3, the printing format is not so constraining here.

The positive aspects of digital printing:

• number of copies up to 1.000 pieces
• ideal for small series of posters, leaflets,….
• personalized printing
• business cards
• easy preparation
• easy repeatability
• printing from Word, Excel, PowerPoint and other SW
• high print speed
• lower cost of finishing work, collation, etc.

The negative aspects of digital printing:

• the price is only economical for higher numbers of copies, compared with the offset technology
• smaller choice of materials suitable for printing on
• the quality of the digital sheet printing, as a rule, does not enable to print artwork reproductions
• it is impossible to use the Panthone colors

The concise description compiled by „Vít Hudec“, a consultant:http://www­.ownway.eu/…pro­graficka/

Articles related to printing:

• Offset printing
• Printing of business cards and labels
• Personalized printing

Offset printing

Offset - the color register

Offset printer

Offset printing technology, which has been known unchanged for more than one hundred years, is based on the principle of successive application of liquid color inks. A color picture is divided into two or more so-called printing plates each of which is designed to transfer one color part of the picture onto the paper. Most frequently, four such plates are applied representing the most widespread color scale CMYK: C – Cyan (azure), M – Magenta (purple), Y – Yellow, K – Black . This application in successive steps results in a color register that produces the desired result.

Offset printing utilizes printing plates, the production of which is not exactly cheap, and they can only be used for a single document you need to print. Having been used in printing, the plates cannot be recycled. Their cost has to be included in the price calculation. Likewise, the cost of preparatory pre-press work on the offset printer is significantly reflected in the final price. It is a very exacting affair indeed. Printing alone, then, is very cheap. On this account, every offset master printer tries to print larger series. The pre-press work on a leaflet being the same, the total price for printing 500 copies will come to approximately CZK 2.300,– (CZK 4,60 per copy). When printing 5 000 copies of the leaflet, the price is going to drop sharply down to CZK 0,68 per copy, while the total price of the entire order is only to rise to CZK 3.400,–.

Quality of printing

The best printing quality available is naturally very sensitive to the quality of the input data. Apart from the register colors, offset technology also prints the so-called spot colors; they are colors that cannot be achieved by combining the CMYK colors and include gold, silver (metallic colors in general), most Panthone colors, reflective (luminous) colors.

Range of materials suitable for printing

Offset printing allows the widest choice of different materials, from low basis weights (50g/m2) up to very high ones (500g/m2). The offset technology can be applied on the largest scale of papers, with the two only limitations being the price criterion and the ability of suppliers to acquire the selected material. Stabilization of ink is effected after the particular ink has become dry on the material.

Formats of printed materials

The biggest printing machines (except for wheel printers) are able to print on the B0 format, which is a paper sheet with dimensions of 1000×1414 mm. However, most often, machines of the B1 – 707×1000 mm and B2 – 500×707 mm print formats are used. The sheer bulk of materials is subsequently, after printing, cut into the desired final format – for instance A4, A5, B5 and the like.

The positive aspects of offset printing:

• the number of copies from 400 up
• profitable printing for large series of posters, leaflets…
• high quality of print and a large choice of materials suitable for printing on
• and other.

The negative aspects of offset printing:

• high requirements for print data
• time-consuming pre-press work and production
• impossibility of printing variable data
• impossibility of printing small series
• and other.

The concise description compiled by „Vít Hudec“, a consultant:http://www­.ownway.eu/…pro­graficka/

Articles related to printing:

• Digital printing
• Printing of business cards and labels
• Personalized printing