Light fastness, in its broadest sense, is the resistance of colours to fading un-der the influence of a light source. Light fastness is one of the most important physical, and therefore visual, properties sought in both pigments and in the inks. Artificial and natural light causes most pigments to fade resulting in co-lour change. The light fastness of inks is important especially in the packag-ing and advertising industries. The posters and advertisements hung on the billboards used especially in outdoor advertising, printed product packaging and other printed products exposed to sunlight require high degree of light fastness. In this study, light fastness and factors affecting the resistance of the colour to the light were investigated and suggestions were made regard-ing high light fastness in terms of printability.

In printing, the most important element is to obtain the correct substrate and ink combination. Transparent white and opaque white are used for the lightening of printing inks, but they are also an important component for the mixing of inks. The primary objective of this study was to assess the result of using transparent and opaque white in mineral oil-based offset printing inks on the rheological and printability properties of these inks as well as the ideal mixing ratios in terms of print quality. Transparent and opaque white were added into the standard offset magenta ink variable ratios. Differences in ink viscosity, tack, and flow (rheological) values affect such parameters as adhesion, transferability, and printing stability in these inks. Prints were made on matt-coated papers of the same grammage with these inks, and contact angle, solid ink density, color strength, and print gloss values of these ink films were measured. Color differences ( ) of inks in comparison to the standard ink were calculated and the effects of transparent and opaque white on the rheological and printability properties of the ink were presented. Finally, the ideal mixture ratios of transparent and opaque white into the ink were determined in terms of print quality and recommendations were presented.

Introduction: Printing inks oil selection is related to the desired nature of the varnish in the ink production. Petroleum-derived mineral oils and vegetable oils can be used in offset inks. Methods: In this study, the behaviors of vegetable- and mineral oil-based inks on uncoated and coated paper surfaces were investigated in terms of printability. Solid tone test prints were done with offset printing of these inks. Print gloss of the printed samples was measured and a light fastness test was implemented on these samples in order to determine the resistance to fading. Absorption behavior and contact angles of the ink-printed films on the test papers were measured with the sessile water drop method depending on time, and surface energies were calculated. Results: On both paper types, linseed–soybean oil-based vegetable ink gave the highest brightness value. The lowest print gloss results on the paper were obtained from soybean oil-based inks. The lowest color change was recorded with mineral oil-based inks on gloss-coated papers. According to the ink-film–surface relation, when the contact angle is high, surface energy decreases and the absorbency of the ink-film is lower. Conclusions: In this study, the behaviors of vegetable- and mineral oil-based inks on different paper surfaces, and the effect on the quality of printability as well as differences, have been evaluated, taking environmental and health factors into consideration.

Accelerating the transition to post-print processes needed in the printing industry and shortening the time the product's release time is closely related to the drying time of the ink film. The drying of fluid ink on the surface of the print substrate, transforming from liquid to solid occurs physically and chemically in several ways. Drying systems can be functional alone on the surface of the printing substrate for an ink film or depending on the chemical content of the ink and the properties of the printing substrate, drying can be achieved at the same time with more than one system.Recently, in order to reduce climate, environmental and health impacts and with the development of technology, significant changes are also being experienced in the printing industry and preferences are changing. In this study, more environmentally friendly LED UV and microwave drying systems that save time and energy together with existing basic drying systems such as absorption, evaporation, oxidation-polymerization and conventional UV used in the printing industry are examined. The advantages of different drying systems to the printing industry, preferred drying systems and new studies on this issue have been evaluated.

In the packaging sector of the printing industry, different coating applications are tried and investigated in order to increase the surface appearance and performance characteristics of paper and cardboard. The printability, water and ink absorption capacity, frictional resistance, light sensitivity of the visual graphical design that are going to be printed on the packaging papers are some of them. In this study, different types of cardboards that are used as a packaging material were chosen and coated with nanocrystalline cellulose (NCC)/PVA at different rates (%). In order to determine effective and economical usage conditions, the coating solutions, at three different concentrations as 3 wt.%, 5 wt. %, 7 wt.%, were prepared. The coating was applied on the test papers, which were at the same weights (350 g/m2) and had different surface properties as matte glossy, bright glossy, American Bristol. NCC/PVA existence on the coated paper surface was confirmed with Fourier Transform Infrared Spectroscopy (ATR-FTIR). The impact of the coating, which was prepared at different concentrations, on the packaging materials was studied with respect to thickness, stiffness, water absorbability, contact angle and surface tension.