June 2015


Gorazd Golob

EDITOR-IN-CHIEF

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2-15

 

Cold foil transfer technology for functional printing

Duy Linh Nguyen1, Alexandra Lyashenko1, Meliksah Ucuncu1, Martin Schmitt-Lewen2, Alexander Weber2, Andreas Henn2, Simon Loeprich1, Edgar Doersam1
E-mail: nguyen@idd.tu-darmstadt.de
1 Technische Universitaet Darmstadt, Institute of Printing Science and Technology, Magdalenenstrasse 2, 64289 Darmstadt, Germany
2 Heidelberger Druckmaschinen AG, Kurfuersten-Anlage 52-60, 69115 Heidelberg, Germany

Abstract

Since some years, several research institutes, institutions and companies are working on the realization of electronic components by innovative methods, which can lead to cost-effective, simplified and flexible production of such products. Among other low-cost technologies such as coating and vapor deposition, printing as an additive structuring process is one focus of research. Another interesting additive printing-related method is cold foil transfer technology or also so-called cold foil stamping. The cold foil transfer technology is conventionally used in the finishing step for various, mostly decorative, printing products. For a real metal effect to be obtained in graphic arts printing so-called cold foils are used, which in most cases have an aluminium layer. The metal is applied by vapor deposition with high demands on the polyester foil properties, so that the metal particles are close together and thus set up a thin homogeneous conductive aluminium layer in the nanometer range. The fact that the cold foils have a metal layer has led to the idea of using this printing method for electronic applications using its conductivity. The following criteria are important for using cold foil transfer processes for printed electronics: electrical conductivity, reproducibility and reliability of such metal layers, especially depending on different printing process settings. In this research, the cold foil is transferred to a substrate in a sheet-fed offset printing press. The samples are measured by using a contactless measurement method. The experiments show a medium to low sheet resistances of the transferred aluminium layer. Furthermore, the conductivity of the aluminium areas on the substrate depend on their location on the much larger substrate sheet. The objective of this research – application of the cold foil transfer technology and determination of its process boundaries for the use in the electronics field – could be confirmed.

Keywords: hot stamping, sheet-to-sheet process, mass production, electric conductivity, printed electronics

JPMTR 057 | 1416 Research paper
DOI 10.14622/JPMTR-1416
UDC 655.1 : 621.38+537.3

Received: 2014-07-15
Accepted: 2015-04-10

A novel method to determine register variation of a press by a densitometry tool

Shahram Hauck1, Sasan Gooran2
E-mail: shauck@beuth-hochschule.de; sasgo@itn.liu.se 
1 Beuth Hochschule Berlin – University of Applied Sciences, Dept. of Information Technology and Media, Luxemburger Straße 10, 13353 Berlin, Germany
2 Linköping University, Campus Norrköping, Dept. of Science and Technology, 60174 Norrköping, Sweden

Abstract

The print quality of a printing machine highly depends on good register variation values. The measuring of register variation is very important for putting a multicolor press in operation or for its repair and service. The manufacturers of print presses also need the evaluation of register variation to develop new products. The current industry standard method for measuring the register variation is based on image processing, which is a very expensive method. It was a great demand to determine the register variation by an alternative and affordable technique. In the present paper we introduce a new method to determine the register variation based on densitometry. In order to create a new method, a special color test target has been designed. The input of the method is the densitometric measurement values, and its output is the register variation value. The results of the method have been compared with those of an image processing method and the correlation coefficient between the results is almost 0.9. Since in the proposed method only a densitometer is needed, it can be considered as a very inexpensive alternative to the image processing methods. The results were also demonstrated to different specialists of a manufacturer of print press and received very positive feedback.

Keywords: sheet-fed printing, printing press, print quality, Neugebauer equation, Murray-Davies equation

JPMTR 058 | 1436 Research paper
DOI 10.14622/JPMTR-1436
UDC 655.1 : 763+035.4 | 535.3 (084)

Received: 2014-09-22
Accepted: 2015-04-28

Effects of awareness to security features on the confidence in banknotes

Osamu Masuda, Marius Pedersen, Jon Y. Hardeberg
E-mail: osamu.masuda@hig.no
The Norwegian Colour and Visual Computing Laboratory, Gjøvik University College, Gjøvik, Norway

Abstract

The value of a banknote is dependent on people’s subjective trust in the banknote, and the resistance against counterfeiting is a key factor of people’s confidence in the banknote. An experiment was conducted to investigate the relationships between the awareness to security features on banknotes and the perceived resistance against counterfeiting in those banknotes. It was found that the more security features subjects found by themselves on a banknote, the more resistant they perceived the banknote, which suggests that people’s awareness to security features affects their confidence in the banknote. The perceived resistance was irrelevant to the number of public security features disclosed by the central banks, but was relevant to the familiarity to the note, which suggests the importance of practical experience with banknotes rather than the knowledge about them only. These findings can give a quantitative ground to the evaluation of the design of security features on banknotes.

Keywords: banknote, security printing, counterfeit deterrence, image quality

JPMTR 060 | 1441 Research paper
DOI 10.14622/JPMTR-1441
UDC 655.1 : 336.74 | 62-759

Received: 2014-11-21
Accepted: 2015-02-02

Security offset printing with twin colors by means of CMYF separation

Branka Morić Kolarić1, Ivana Žiljak Stanimirović2, Ivana Bak1
E-mail: bmoric@nn.hr
1 Narodne novine d.d. Printing Operations, Savski gaj XIII put 13, HR-10020 Zagreb, Croatia
2 Faculty of Graphic Arts, University of Zagreb, Getaldićeva 2, HR-10000 Zagreb, Croatia

Abstract

A new method of security printing is introduced in this work, thus creating highly protected documents by ink management in three spectrally separated ranges. A numerical experimental color setting has been developed, considering ink properties in three wave ranges: 200–400 nm, 400–700 nm and 700–1000 nm. Separation is carried out with process and spot inks, aiming at concealing the graphic in visible spectrum. Such a graphic can be recognized instrumentally in the ultraviolet (F) and infrared (Z) spectra. Extending the Infraredesign method, the ultraviolet spectrum is included through the properties of the dark brown UV ink, thus giving fluorescent green in UV spectrum, while the absorption value is 38 % for parameter Z in the NIR spectrum. A separate, third image is visible by the naked eye. By algorithmic mixing of F-ink, having absorption properties in UV and IR ranges, a unique solution for the security printing of documents and valuables is accomplished. CMYF method differs from the CMYKIR method, since the K ink does not have the same properties, while their Z factor is completely different under the same printing conditions. With this new method – CMYF separation – formulations and standards are set for determining the differences between the original and the forgery.

Keywords: security design, fluorescent ink, document protection, hidden graphics, spectrophotometry

JPMTR 059 | 1432 Research paper
DOI 10.14622/JPMTR-1432
UDC 655.1 : 763 | 62-759 (084)

Received: 2014-08-11
Accepted: 2015-01-19

Multi-channel dot-off-dot halftoning compensating for slightly chromatic gray inks

Sasan Gooran and Paula Zitinski Elias
E-mails: sasan.gooran@liu.se; paula.zitinski.elias@liu.se
Dept. of Science and Technology, Linköping University, Campus Norrköping, 601 74 Norrköping, Sweden

Abstract

Printing using more than four ink channels visually improves the reproduction but causes challenges with the ink layer thickness that could lead to ink bleeding and color inaccuracy. A color image is commonly prepared for print by first being separated into the colorant channels the intended print device utilizes. The separations are usually halftoned independently, resulting in random dot overlap with possible spots where all colorants are printed. A multilevel halftoning algorithm that processes each channel so that it is printed with multiple inks of the same hue value has already been applied to three achromatic inks – photo gray, gray, black – in a real paper–ink setup. Results proved a successful multilevel halftone implementation workflow using multiple inks while avoiding dot-on-dot placement. However, in this approach, the gray inks were assumed to be neutral and lighter versions of black, an assumption that may cause a ΔE*ab color difference as high as 5. In the present paper an alternative approach, based on dot-off-dot halftoning avoiding dot overlap, is proposed and applied to the same three inks. A look-up table driven separation procedure of the original image into the three channels is also proposed, which, combined with dot-off- dot halftoning, results in a ΔE*ab color difference not larger than 1.8. Results show that the dot-off-dot halftoned images are visually pleasant without any artifacts in tone transitions. The proposed approach has three main advantages to the commonly used independent halftoning. One being that dot overlap between different inks is completely avoided, i.e. photo gray, gray and black in the present work. The other one is that the results are less grainy compared to independent channel halftoning. The third one is that dot-off-dot halftoning consumes less ink than independent halftoning when reproducing the same color.

Keywords: multilevel halftoning, dot-off-dot halftoning, dot gain compensation, multi-channel printing, graininess

JPMTR 061 | 1440 Case study
DOI 10.14622/JPMTR-1440
UDC 655.1 : 776.7

Received: 2014-11-18
Accepted: 2015-05-05

The effectiveness of multilingual marketing/advertising messages by Nigerian manufacturers

Floribert Patrick Calvain Endong
E-mail: floribertendong@yahoo.com
Department of Theatre and Media Studies, University of Calabar, P.M.B. 1115, Calabar, C.R.S – Nigeria

Abstract

A well designed product’s package is very essential for effective communication as it facilitates the delivery and accurate decoding/interpretation of the marketing message(s) it contains. However, communication can become complicated when the marketing message is conceived to be bilingual or multilingual in view of targeting linguistically heterogeneous consumers. Because multilingual messages/texts’ designers usually make extensive use of typography and graphic design (to differentiate between linguistic codes involved in the composition of the message and to ultimately make these compositions readable and intelligible to potential decoders), we used a textual analysis and a user study to reveal incidences of reduced effectiveness – nay ineffectiveness – of marketing messages featuring on the packages of some products made in Nigeria or marketed by Nigerian firms. This study is based on a content analysis and two focus group discussions. The content analysis involved a dozen marketing messages by Nigerian manufacturers from the food and drugs sectors. It considered multilingual phrases and sentences contained in the messages as units of analysis. The paper presents a critique of these multilingual marketing messages with respect to the use of typography and graphics. It analyses the presence and use of typographical markers and graphics in advertising messages to differentiate between languages. It reveals that most Nigerian designers dominantly use punctuation and less spacing to differentiate between the linguistic codes employed in the construction of marketing/advertising messages. Furthermore, some of the multilingual phrases and sentences do not have typographical markers to emphasize these linguistic differences. The texts therefore remain mostly compact and hardly or less legible. The two focus group discussions conducted with multilingual and unilingual expatriates helped elicit consumers’ capacity to spot information presented in the multilingual message as well as explain how (in)effective the advertising messages may be in explaining the characteristics of the products been advertised. The discussants identified a number of weaknesses that pointed to the reduced effectiveness of the advertising messages.

Keywords: typography, graphic design, multilingual marketing messages, effective communication

JPMTR 062 | 1433 Case study
DOI 10.14622/JPMTR-1433
UDC 658.8=00 (669)

Received: 2014-10-07
Accepted: 2015-04-29