Search

This paper is an experimental and statistical approach to find out an optimal solution for the high print quality reproducible by flexographic printing on coated and uncoated substrate using Taguchi's Grey Relational Analysis method. The halftone image composed of round and square shaped dots with AM screening and the anilox roller with three different screen rulings are employed at different trial runs of experiment. Total of 12 numbers of experimental runs with different combinations of paper grades, halftone dot shapes and anilox roller rulings are employed in the experiment to investigate its influence on the final print quality. The print quality evaluation is based on the assessment of Optical Ink Density (solid areas), Dot Gain, Hue Error and Print Contrast using Taguchi's Grey Relational Analysis method. Based on the Taguchi's GRA score, the optimal solution for the high print quality is prioritized. This paper aims to distinguish the influence of substrate, halftone dot shape and anilox cell ruling in the final print quality of flexographic process. Also, it demonstrates the scope of applying Taguchi's Grey Relational Analysis in the printing field to find out an optimal solution for the multiple criteria-based decision-making activities. [ABSTRACT FROM AUTHOR]

Some documents in the Arab Republic of Egypt face a great challenge, which is the problem of short life span, and it is worth noting here that the global trend and also in the Arab Republic of Egypt recently is moving towards the use of polymers as an alternative to traditional paper materials in many important documents, and therefore the research has addressed the possibility of printing on raw materials. Teslin polymers, facing many challenges, including print quality when printed on any of the digital printing techniques in terms of determining the most appropriate digital techniques for printing on plastic Teslin material to obtain the required print quality by measuring both (Lab values of colour, density, dot gain and trapping). And to achieve this goal, this research has dealt with the theoretical, practical and analytical study of both the raw material that has been experimented with and the digital printing techniques used in the practical experiments of printing on the Teslin material, which is an inkjet technique using the Com Color GD 9630 Riso printer, and the dry electro photographic technique using Library printers with limited production, which is the HP Color LaserJet Enterprise M553 printer, and also the dry electro photographic technology using quantum production (mass production) printers a Ricoh C7200 SL printer, and liquid electrophotography technology was used using the HP Indigo 7800 printer, and the study concluded that The most suitable technology for digital printing on the two-fold material is the Dry electrophotography technology using limited-production library printers, which is the HP Color LaserJet Enterprise M553, and also dry electrophotography technology using quantum printers, which is the Ricoh C7200 SL, and that inkjet technology using the Com Color GD 9630 Riso printer is not suitable for printing.

Modern logo design is characterized by its ability to convey information through the use of various images and text compositions. These designs often use simple elements such as lines to capture the essence of a product. When using thermochromic inks in logo design, it is important to consider their composition and behavior, as they differ significantly from conventional printing inks. This study aimed to determine the resolution capabilities of the dry offset printing technique when using thermochromic ink, with the ultimate goal of optimizing the thermochromic ink printing process. Horizontal and vertical lines were printed using both thermochromic and conventional inks to compare the edge reproduction characteristics of the two ink types. Moreover, the impact of the type of applied ink on the share of mechanical dot gain of the print was investigated. Additionally, modulation transfer function (MTF) reproduction curves were generated for each print. Moreover, scanning electron microscopy (SEM) was conducted to investigate the surface of the substrate and prints. It was found that the quality of the printed edge produced by thermochromic inks can rival that of conventional inks. Thermochromic edges showed lower raggedness and blurriness values for horizontal lines, whereas line orientation proved to be insignificant in the case of vertical lines. MTF reproduction curves confirmed higher spatial resolution for vertical lines in the case of conventional inks, whereas they were identical for horizontal lines. The share of mechanical dot gain is not highly influenced by the ink type. SEM micrographs confirmed that the conventional ink smooths out the micro-roughness of the substrate. However, on the surface, the microcapsules of thermochromic ink (measuring 0.5–2 µm) are observable. [ABSTRACT FROM AUTHOR]

Flexography prints on non-absorbent as well as absorbent substrates using liquid ink. With developments in photopolymer plate and anilox roll manufacturing technology, we can print half tone with screen frequencies exceeding 150 LPI (Lines per Inch) where the print quality can be comparable with offset printing results. This has helped flexographic printer to reproduce the blackand-white, single colour tone and full colour graphic original, satisfying the printing and packaging needs of many customers. But unlike other printing technologies in flexographic printing screen frequency of plate i.e. image carrier and engraving line frequency of anilox roll collectively affect the smoothness and uniformity of reproduced half tone image. Furthermore, the LPI of the screen used in plate making also adds to variation in tonal reproduction. In the presented work 3 line frequencies expressed in CPI (Cells per Inch) of anilox roll and 5 screen frequency of image carrier are selected and their effect on print characteristics is studied using the plot of theoretical dot area against apparent dot area. Given the sizable capital investment involved in manufacturing of anilox roll, this work is directed at finding the optimum combination of screen frequency and line frequency required to achieve tonal balance. [ABSTRACT FROM AUTHOR]

Some documents face the problem of damage as a result of their short life span, and it is worth noting here that the global trend and also in the Arab Republic of Egypt recently is moving towards the use of polymers as an alternative to traditional paper materials in many important documents, and this corresponds to facing many challenges, including print quality when printing on Polymeric materials, and one of the most famous modern printing methods is liquid electro photographic technology such as Indigo printers, which combine the two traditional litho-offset printing methods in terms of using a rubber medium to transfer the image in printers and the electro photographic digital printing in terms of the mechanism of exposure to the image using the electrostatic image, so it is called digital offset printing. It was necessary to determine the most suitable polymeric materials used in the Arab Republic of Egypt to print on it using liquid electrophotography to obtain the required print quality (color measurement, density, point growth), and to achieve this goal, experiments were carried out using many polymeric materials on the HP Indigo 7800 printer, and results were reached. Experiments to that ores (special synthetics resin paper) SSRP, Poly art material does not accept liquid electro photographic printing, and it was the best print quality on Teslin polymers SP even though it was lower than the standard values of ISO 12647-2, although SYNAPS polymers OM gave good results in Some quality measurements, as there are no reference values for the quality measurements of polymer materials, and accordingly the researcher concluded that it is not recommended to print on materials (SSRP, Poly art) using liquid electrophotography, as it is not acceptable to print on it with this printing technique, and that the best material is when using The liquid electro photographic technique is Teslin polymers SP, as it was the most suitable polymeric material used in the Arab Republic of Egypt to print on it with this technology in terms of quality.

The present paper presents a comparative analysis of two printing methods, namely: offset printing and digital printing. Specifically, the analysis involves identifying the constructive solutions of the printing machines, determining the technological phases involved in printing the same type of product - magazine, the length of time needed to make them as well as aspects regarding the quality of the print (optical density, dots gain, colors). The study was carried out on the MAN Roland 704 offset printing machine and the Ricoh Pro C9210 digital printing machine. This paper highlights technological aspects that will bring to light the best method for printing typographic products in the shortest time and of the highest quality.

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A standard color gamut can be obtained with CMYK samples that are printed with an offset printing system according to the ISO 12647-2:2013. It is possible to enhance or widen the color gamut during the printing process by interfering with the density and dot gain characteristics. Printing with a wider color gamut provides a more vivid area and more depth in color. In this study, print trials were conducted at first with standard values (density, dot gain and such). Then another trial was conducted by changing the density values respectively during the trial. Ink density values for all colors were decreased from the standard value as -0.15D, -0.30D and then increased as +0.15D, +0.30D. Color gamuts of the trials were calculated and compared at the end. It is found that ink density values directly affect color gamut in offset printing. It is also found that the color gamut decreases equally when ink density values decrease and vice versa. However, some printing problems occurred with high density values even though it gave an expanded color.

This article is focused on the impact of different binder mixtures on the performances of paper surface and printability. The coating properties were studied with the chosen silica pigment, and the binder consisted of vinyl acetate copolymer and polyvinyl alcohol with different ratios, followed by the measurement of smoothness, whiteness, and surface strength. The inkjet image quality was assessed using water-based inks. The print density, dot gain, and line quality were analyzed. The results showed that the surface performance and printability were affected by the composition of the binder. With the decrease of vinyl acetate copolymer and the increase of polyvinyl alcohol, the surface smoothness and strength decreased, and the penetration and diffusion of the ink changed as well. When the binder mixture was used with proper ratio, a larger solid density, smaller dot gain, and higher definition can be achieved, which were better than using either one of them alone.

Copyright of Transactions of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A standard color gamut can be obtained with CMYK samples that are printed with an offset printing system according to the ISO 12647-2:2013. It is possible to enhance or widen the color gamut during the printing process by interfering with the density and dot gain characteristics. Printing with a wider color gamut provides a more vivid area and more depth in color. In this study, print trials were conducted at first with standard values (density, dot gain and such). Then another trial was conducted by changing the density values respectively during the trial. Ink density values for all colors were decreased from the standard value as -0.15D, -0.30D and then increased as +0.15D, +0.30D. Color gamuts of the trials were calculated and compared at the end. It is found that ink density values directly affect color gamut in offset printing. It is also found that the color gamut decreases equally when ink density values decrease and vice versa. However, some printing problems occurred with high density values even though it gave an expanded color. [ABSTRACT FROM AUTHOR]

Subtractive-Color-Reproduction is the fundamental mechanism in 4-color process printing, which employs CMYK (cyan, magenta, yellow and black) dots for color reproduction. Watermarks embedded in RGB images are distorted when the image is transformed from what to process color for printing usage. Based on the feature of CMYK color space and human visual system, this paper presents a robust CMYK watermarking algorithm for printing images, which embeds an informative watermark and a structure template signal in DCT domain of the Yellow information channel and DFT domain of the black information channel respectively. The embedded template enables robustness against geometric distortions in the print-scanning process. Another spatial visual mask is proposed to reshape the embedded energy after it is inverted to the spatial domain, which significantly improves the color fidelity and the image quality. In addition, a dot gain compensation model is put forward for color correction. A series of proof tests have been carried out on an offset press, which show that the watermark preserves the fidelity of the image and can be extracted with a high quality; moreover, a remarkable fidelity of color and tones on printed copies is well preserved. [ABSTRACT FROM AUTHOR]

Pad Printing is most direct way of printing. Mechanic Dot Gain means physical growing of screen dot with printing pressure. Dot Gain in Pad Printing is a significant parameter effecting printing quality. Factors such as structure of swage block material used, ink fluidity, stiffness of spool silicon, type of mould used, display depth, angle of stripper knife, stress adjustment of printing press effect dot gain. How these variance effect to screen dot should be known and pressure studies should be made in conditioned environment. The purpose of this study is to determine how the tram frequency of the images printed by buffer printing affects the point gain value. In the study, rough and coated papers have been chosen as swage block material for Test printing studies. Spectrophotometer and dot gain values have been measured over pressure results made on rough and coated papers in frame optimum parametres with the aim of providing qualified pressure results. Four test scales have been prepared in which there have been different screen ton values having 40-54-60 and 70 Lpc screen ruling. In order dot gain to be measured on test scales, film, blcok and printing, areas having screen ton values from %1 to 2, 3,5 10, 20, 30, 40, 50, 60, 70 have been constituted. Steel form, which is 2 mm thick, by Kodak Freundorfer Druckplat has been used in pressure test studies. Steel form has been placed into ink tank, the size of which is 150.250 mm. Areas having screen ton values of screened scale with 40, 54, 60 and 70 Lpc screen rulings, dot gain values on film, block, rough and coated paper were measured with Spectrophotometer. Ink type which has been used in test printings are parametres whose viscosity, spool stiffness, physical structure of spool, stiffness and thickness of spool stripper knife, printing pressure and printing speed have been held stable. [ABSTRACT FROM AUTHOR]

Printing systems operate in general as a system of color its color scale is limited as compared with the system color satellite images. Satellite image is building from very small cell named pixel, which represents the picture element and the unity of color when the image is displayed on the screen, this unit becomes lesser in size and called screen point. This unit posseses different size and shape from the method of printing to another, depending on the output resolution, tools and materials of each system scribal. Lithography using ink pasta, the laser uses a powder color. Ink-jet uses liquid inks water and photography based on the optically sensitive colors. All of these factors and substances affect the quality of the printed image. In this paper different printing systems were used to print an image of SPOT-4 satellite, caver part of Sharm Elshekh area, Sinai, Egypt, on the same type of paper as much as possible, especially in the photography. This step is followed by measuring the experimental data, and analyzed colors to determine the best printing systems for satellite image printing data. The laser system is the more printing system where produce a wider range of color and highest densities of ink and access much color detail. Followed by the offset system which it recorded the best dot gain. Moreover, the study shows that it can use the advantages of each method according to the satellite image color and quantity to be produced.

The resolution is considered as one of the most important factors which controls the quality of the printed image, whether input resolution (digital camera–scanner) or output resolution (printer–computer to film, plate or paper). The research discusses the accuracy of the input resolution of image processing equipment for digital files through using two different sets of resolution, one low (72 dpi) and another high (300 dpi) and to print the files by using a digital toner printer. Which produce with a high output resolution up 2400 × 2400 dpi and use the same type of paper for printing these files. Then quality measurements (characteristic curve–dot gain–density) are performed to determine the accuracy effect of input resolution on the quality of the printed images. In this research the researchers used scientific and practical analysis methods to analysis this problem and to determine the accuracy effect of input resolution on the quality of printed images. It has been concluded that the differences of the input resolution do not obviously affect of quality measurements that the results are largely close, despite the quality difference of the two cases (low resolution–high resolution) are easily noticed to the naked eye while zooming images at appropriate level.

The objective of this study is to analyze and compare the print quality by offset printing process on uncoated paper for matching the quality on par with ISO 12647 standards. A standard test form that contains different control strips for densitometric and colorimetric measuring has been used to define the optical density and color difference of the main process ink colors like cyan, magenta, yellow and black while printed on four-color Heidelberg CD102 sheet-fed offset printing press. The results are important from scientific and practical point of view. By applying the regression analysis methods, the correlation between the optical density deviations ΔD from the optimal values and color difference ΔEab represented by the following regression model of Quadratic equation: ΔEab = a + bΔD + cΔD² (y = a + bx + cx²) has been ascertained. By using the mathematical regression model, identification of the suitable values of every color on the output in offset printing, can be easily done. The experimental result of print density and LAB values on uncoated paper is matching with ISO 12647-2 Graphic technology - process for the production print. [ABSTRACT FROM AUTHOR]

Printing systems at the flooring and covering tile industry allow the achievement of an adequate transference from design to the final piece. Technical evolution of each one of these systems permits to make it almost independently from the printing system used. Besides, it could be said that in the last few years it has arrived at an outstanding increase in the variety of designs in terms of definition and quality (being understood as an increase in the resolution). As far as the “theoretical” precision is concerned, they entail an increase in printing problems, being important in the product. A higher printing resolution implies the appearance of new problems in tone stability provoked by the higher difficulty in the control of the printing dot. This problem is specially grave in ceramics, where tone homogeneity of the product is required. In this paper interaction between variables related to design, as well as printing systems, and characteristics of physical and chemical properties of the dyes that affect stability of designs in ceramic flooring and covering tiles are described. The aim is to stand out the necessity to systematically control as many factors as possible in order to reduce production tone variability. This piece of work is part of a research project financed through FEDER-CICYT funds, focused on the minimisation of tone variability in the ceramic tile industry.Los sistemas de impresión en la industria del pavimento y revestimiento cerámico permiten la realización de una adecuada transferencia del diseño a la pieza final. La evolución técnica de cada uno de estos procesos de impresión permite hacerlo casi con independencia del tipo de sistema que se utilice. Además, podemos decir que, en los últimos años, se ha llegado a un notable aumento de las posibilidades en cuanto a diseños en su forma y su calidad (entendida esta como aumento en la resolución). Las mejoras en cuanto a la precisión “teórica” de las técnicas suponen un aumento de problemas de impresión de importancia en el producto. Un aumento en la resolución de impresión supone la aparición de nuevos problemas en la estabilidad del tono producido por la mayor dificultad de control de punto de impresión. Este problema es especialmente grave en la cerámica donde se exige una homogeneidad tonal de todo el producto fabricado. En el presente artículo se describen las interacciones que existen entre las variables de diseño, los sistemas de impresión y las características físico-químicas de las tintas que afectan a la estabilidad de los diseños en pavimentos y revestimientos cerámicos. El objetivo es destacar la necesidad de controlar sistemáticamente los máximos factores posibles con el fin de reducir la variabilidad tonal productiva. El presente trabajo es parte de un proyecto de investigación centrado en la minimización de la variabilidad tonal en el sector cerámico financiado con fondos Feder-Cicyt.

Spectral reflection prediction models, although effective, are impractical for certain industrial applications such as self-calibrating devices and online monitoring because their calibration requires specific color-constant calibration patches. Using the CMYK Ink-Spreading enhanced Yule-Nielsen-modified Spectral Neugebauer model (IS-YNSN), we propose a method to recover the colorant reflectances (Neugebauer primaries), the ink-spreading curves, and the Yule-Nielsen n-value using only tiles extracted from printed color images. There is no prior knowledge about the reproduction device. Thanks to a set of constraints based on principal component analysis and the relationships between composed Neugebauer primaries and the ink transmittances, good approximations of the Neugebauer primaries are achieved. These approximations are then optimized, yielding an accurately calibrated IS-YNSN model comparable to the one obtained by classical calibrations. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 216-233, 2014; Published online 23 February 2013 in Wiley Online Library (). DOI 10.1002/col.21800 [ABSTRACT FROM AUTHOR]

Difference in dot gain using various additives to the damping solution was investigated on two offset web presses. Dot gain was measured using a densitometer and calculated considering CIE L*a*b* coordinates. It was found that while using a non alcohol additive instead of the alcohol one, dot gain became smaller and printing stability was lower. Changes in dot gain depend on the ink that may vary in colours. The influence of changes in dot gain on the colour was determined. Besides, it was found that differences in colour were unacceptable in many cases. Article in Lithuanian Vilgymo skysčio sudėties įtaka rastrinių taškų padidėjimui spausdinant Santrauka Darbe tirta vilgymo skysčio sudėties įtaka rastrinių taškų padidėjimui spausdinant dviem ritininėmis spausdinimo mašinomis. Taškų padidėjimas matuotas densitometru ir skaičiuotas pagal CIE L*a*b* koordinates. Nustatyta, kad pakeitus spiritinį vilgymo skysčio priedą nespiritiniu rastrinių taškų padidėjimas sumenksta ir sumažėja spausdinimo stabilumas. Taškai padidėja nevienodai esant skirtingoms spalvoms. Taip pat ištirta, kad rastrinių taškų didėjimo pokyčiai keičiant vilgymo skysčio priedus iškraipo spalvas ir daugeliu atvejų spalvų skirtumai būna neleistino lygio. Reikšminiai žodžiai: taško dydis, rastrinio taško padidėjimas, spalvų parametrų kitimas.

Abstract: Printing systems operate in general as a system of color its color scale is limited as compared with the system color satellite images. Satellite image is building from very small cell named pixel, which represents the picture element and the unity of color when the image is displayed on the screen, this unit becomes lesser in size and called screen point. This unit posseses different size and shape from the method of printing to another, depending on the output resolution, tools and materials of each system scribal. Lithography using ink pasta, the laser uses a powder color. Ink-jet uses liquid inks water and photography based on the optically sensitive colors. All of these factors and substances affect the quality of the printed image. In this paper different printing systems were used to print an image of SPOT-4 satellite, caver part of Sharm Elshekh area, Sinai, Egypt, on the same type of paper as much as possible, especially in the photography. This step is followed by measuring the experimental data, and analyzed colors to determine the best printing systems for satellite image printing data. The laser system is the more printing system where produce a wider range of color and highest densities of ink and access much color detail. Followed by the offset system which it recorded the best dot gain. Moreover, the study shows that it can use the advantages of each method according to the satellite image color and quantity to be produced. [Copyright &y& Elsevier]

Today's spectral reflection prediction models are able to predict the reflection spectra of printed color images with an accuracy as high as the reproduction variability allows. However, to calibrate such models, special uniform calibration patches need to be printed. These calibration patches use space and have to be removed from the final product. The present contribution shows how to deduce the ink spreading behavior of the color halftones from spectral reflectances acquired within printed color images. Image tiles of a color as uniform as possible are selected within the printed images. The ink spreading behavior is fitted by relying on the spectral reflectances of the selected image tiles. A relevance metric specifies the impact of each ink spreading curve on the selected image tiles. These relevance metrics are used to constrain the corresponding ink spreading curves. Experiments performed on an inkjet printer demonstrate that the new constraint-based calibration of the spectral reflection prediction model performs well when predicting color halftones significantly different from the selected image tiles. For some prints, the proposed image based model calibration is more accurate than a classical calibration. [ABSTRACT FROM AUTHOR]

Abstract: The resolution is considered as one of the most important factors which controls the quality of the printed image, whether input resolution (digital camera–scanner) or output resolution (printer–computer to film, plate or paper). The research discusses the accuracy of the input resolution of image processing equipment for digital files through using two different sets of resolution, one low (72dpi) and another high (300dpi) and to print the files by using a digital toner printer. Which produce with a high output resolution up 2400×2400dpi and use the same type of paper for printing these files. Then quality measurements (characteristic curve–dot gain–density) are performed to determine the accuracy effect of input resolution on the quality of the printed images. In this research the researchers used scientific and practical analysis methods to analysis this problem and to determine the accuracy effect of input resolution on the quality of printed images. It has been concluded that the differences of the input resolution do not obviously affect of quality measurements that the results are largely close, despite the quality difference of the two cases (low resolution–high resolution) are easily noticed to the naked eye while zooming images at appropriate level. [ABSTRACT FROM AUTHOR]

This review summarises the developments in adhesion, VOC emissions, coatings, transparent conductive coatings, hybrid organic-inorganic coatings, UV curing, biocidal coatings, paints, weathering, wood coatings, surface treatment of concrete, metal corrosion, pigments, film formation, printing, modelling fluid flow in printing, dot gain and inkjet printing reported in Surface Coatings International Part B: Coatings Transactions, 88, 2005. [ABSTRACT FROM AUTHOR]

Copyright of Surface Coatings International Part B: Coatings Transactions is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Surface Coatings International Part B: Coatings Transactions is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)