June–July 2017

A letter from the editor

Gorazd Golob

Editor-in-Chief

E-mail: gorazd.golob@jpmtr.org/journal@iarigai.org

The first issue of the Journal in 2017 is published with some delay and in slightly more modest volume of the pages as usual, with only three research papers published. Attentive readers will notice some changes in typography and design. The Cambria font was chosen, since it provides better legibility on screen, thus fewer problems are expected, specially when writing equations in MS Word Equation Editor program, where very similar Cambria Math is used as default font. The lay-out was also slightly redesigned, changed and improved, so it is now closer to generally estab- lished typographic rules.
Small, but significant changes have been introduced in the Guidelines for Authors. I would like to emphasize the respect for ethical rules in the field of publishing in scientific journals. Widely internationally accepted ethical stand- ards adopted by the Committee on Publication Ethics (COPE), whose members are the most important publishers of scientific journals – including Springer, whose ethical rules were taken into account so far – are now accepted as a set of ethical rules also for the Journal of Print and Media Technology Research. The COPE guidelines for authors, peer reviewers and editors, available at https://publicationethics.org/resources/guidelines are the backbone of ethical scientific research and publishing of the research results. A brief summary of these rules is published in the Guidelines for Authors of the Journal, so we may reasonably hope and expect that basic ethical standards will be consistently taken into account by the authors, peer reviewers, editors and all those who are in any way linked to the research and publication of their results. Firmly established ethical standards are a prerequisite for recognition of the Journal and its classification in the list of scientific journals.

Similarly, an important part of each article is an overview of the theoretical background from previous publications and research results of other authors, which is evident from the references. At the Journal, the Harvard system of refer- encing is used, which exists in several versions. During editing we have been leaning on the version used by the Anglia Ruskin University, and now we have also obtained their consent for the use of the Guide to Harvard style of Referencing, 6th edition, 2016, available at https://libweb.anglia.ac.uk/referencing/files/Harvard_referencing_2016.pdf for fur- ther and consistent use.

The application of a uniform system of referencing enables the access and processing of the bibliographic data from the references that allows evaluation and classification of the Journal as an important source in the research field of print and media technology. The Journal is currently listed in several national and international lists of scientific jour- nals, but also it is in the evaluation process at Scopus and Web of Science, which calculate and publish important and in academic circles internationally and well known Journal Impact Factor. Only the quality of the papers published in the Journal, their citation frequency in other recognized scientific journals and citations of the papers from the Journal in other Journals can improve the positioning of the Journal in different indexing systems.

The currently published research papers have dealt with challenges in the field of quality of printed holograms, print quality and accuracy of colour reproduction and the use of statistical methods for evaluation of varnish for textured effect. They have a common approach in objective evaluation of the quality of prints and their effect on the observer
– the end user, using a variety of measurement and statistical methods. Improvement of the quality of prints and anal- ysis of user experience is a research area that remains interesting together with the dominant direction of research in the fields of printed electronics, functional printing and 3D printing.
Associated editor Markéta Držková (marketa.drzkova@jpmtr.org) has again prepared an overview of innovations in the field, including the review of developments relating to drupa fair, new patents and interesting books within the areas of nano-materials, infographics, colour reproduction, packaging and from other areas of printing technology. In the academic Bookshelf three doctoral theses are presented, all in the field of printed electronics and sensors, which is obviously a very topical research area. The review of events shows on the intense interest for cooperation and knowl- edge exchange of the professionals and researchers from the industry and academic institutions in the field.

The Journal of Print and Media Technology Research is the leading international publication in the field, even though it does not reach recognition comparable to established journals from the border areas in papermaking industry, colour science, imaging, packaging and advanced materials. Finally, recognition and inclusion on the lists of recognized jour- nals can only be achieved in cooperation, particularly through the publication of high-quality scientific and research papers that will be referenced and cited in other journals. Call for papers is open and I hope that more authors will decide for submissions to the Journal, giving us, editors and reviewers an opportunity for fast and high-quality publication.

Ljubljana, April 2017

JPMTR 092 | 1701 Research paper

DOI 10.14622/JPMTR-1701

UDC 005.6:778.38-023.7/535.6

Received: 2017-01-23

Accepted: 2017-03-16

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1-17

 

Quality control of embossed holograms by measuring gloss and color values

Pauline Brumm1, Edgar Dörsam1, Duy Linh Nguyen1 and Martin Schmitt-Lewen2

1 Technische Universität Darmstadt, pauline.brumm@stud.tu-darmstadt.de Institute of Printing Science and Technology, doersam@idd.tu-darmstadt.de Magdalenenstr. 2, 64289 Darmstadt, Germany

2 Heidelberger Druckmaschinen AG, martin.schmitt-lewen@heidelberg.com Alte Eppelheimer Str. 26, 69115 Heidelberg, Germany

Abstract

Embossed holograms are increasingly often used for the decorative refinement of printed products. So far, there has not been much scientific research about quality control of embossed holograms as well as research about the influence of the background color on the quality of embossed holograms. For this purpose, hologram samples with different background colors were produced in a manual experiment, using the principle of UV embossing. At first, the quality of the samples was evaluated through a visual experiment. The conceptual design of that experiment was part of this research. Second, gloss and color values were measured with conventional hand-held measuring instruments used by the graphics industry. Color measurements were conducted with an X-Rite MA98 multi-angle spectrophotometer and measurements of gloss values with a BYK micro-TRI-gloss gloss meter. The comparison of the results of the visual experiment and the color measurement led to the conclusion that conventional color measuring instruments can eval- uate the influence of the background color on the quality of embossed holograms. It was found out that calculating the color difference ∆E*ab between background color and sample can be used to recreate the results of the visual experiment, whereas the samples’ chroma C*ab is not suitable for evaluating the influence of the background color. The number of provided measuring geometries is a limitation of this approach. Moreover, the comparison of the results of the visual experiment and the gloss measurements showed that conventional gloss meters cannot evaluate the influence of the background color. However, conclusions concerning the UV embossing process can be drawn from a sample’s gloss. This suggests the usage of gloss measurement for process control.

Keywords: micro embossing, UV curing, visual experiment, nickel shim, multi-angle color measurements

JPMTR 093 | 1509 Research paper

DOI 10.14622/JPMTR-1509

UDC 655.1-021.465:535.3:774.8

Received: 2015-11-19

Accepted: 2017-04-29

Print quality and color accuracy of spectral and colorimetric reproduction

Radovan Slavuj1,2, Ludovic G. Coppel1,3, Irina Ciortan1, Peter Nussbaum1 and Jon Yngve Hardeberg1

1 The Norwegian Colour and Visual Computing Laboratory, slavujr@gmail.com Teknologiveien 22, 2802 Gjøvik, Norway ludovic.coppel@gmail.com

2 Radovan Slavuj, Pavla Micunovica 9, irina.ciortan@gmail.com
24300 Backa Topola, Serbia peter.nussbaum@hig.no

3 Ludovic G. Coppel, Bolindervägen 79, SE-17674, Järfälla, Sweden; E-mail: jon.hardeberg@hig.no

Abstract

When reproducing an image by means of printing, the most common concerns are to have good colors and the least perceivable artefacts. These two concerns are most conveniently conveyed via two common reproduction goals: color accuracy and image quality. The goal of this paper is to evaluate how color accuracy aim relates to printed image qual- ity, the attribute usually tight to the method of halftoning. In order to provide a relation between these two different goals, spectral and colorimetric color management workflows are paired with different halftoning methods. Image quality metrics is employed both on the output from the color separation process and on the print output. Overall, spectral reproduction used in this paper showed higher color accuracy but lower image and print quality score, even if combined with state of the art halftoning methods.

Keywords: reproduction workflow, halftoning, image quality, spectral reproduction, multichannel printing

JPMTR 094 | 1615 Research paper

DOI 10.14622/JPMTR-1615

UDC 667.6-023.731 | 535-3

Received: 2016-12-03

Accepted: 2017-03-02

Analysis of UV varnish for textured effect

Shrikant Tora1, Sanjay Sharma2 and Pratik Borude3

1 14/110, Gandhi Nagar, Akkalkoat Road, Solapur, Maharashtra, India-413006 shrikant.tora@yahoo.com

2 Jabalpur, MP, India-482001 sanjay_shm@yahoo.com

3 Pune, Maharashtra, India-411009 pratik.borude.1994@gmail.com

Abstract

Packaging and especially printing industry is experiencing an exponential growth in terms of customer demands. Owing to these demands, UV varnish is playing a major role, which is preferred over lamination due to environmental issues and cost. The UV varnish can give gloss or matte finish. Textured effect on the surface can be achieved by blend- ing gloss finish over matte. Various textures can be achieved by varying the blend of solutions, ratio, viscosity, surface tension, etc. Among varnishing parameters that affect the results are UV-lamp intensity, speed of varnishing and screen ruling of anilox cylinder. The texture created in such a manner, needs to be evaluated with respect to the topographic index to find an optimum combination of the parameters to achieve a particular textured pattern.

Keywords: surface finish, topographic index, offset printing, coating process parameter, image analysis