The measurability and predictability of the printing process are influenced by the impact of various coating methods. Besides enhancing and protecting the printed product, these methods can alter the colorimetric properties of spot colors across different wavelengths. Prediction models based on ink trapping formulas were analyzed, particularly those from Deshpande, Green, and Hoffstadt, designed to forecast colorimetric values in overprinted spot color scenarios. This study examined the influence of coating methods on the colorimetric properties of spot colors and evaluated the applicability of the prediction model for these conditions. Spectrophotometric and densitometric methods, combined with mathematical analysis, were used to quantify the degree of color change induced by different coatings. The findings clearly indicate the extent of colorimetric changes in spot colors resulting from various coating applications. They also highlight the potential, albeit limited, application of this model in predicting color changes for improved process repeatability and predictability. While the prediction method analyzed in this study proved inadequate for coating-over-spot-color scenarios, it remains useful for predicting colorimetric shifts in spot-on-spot-color overprinting. The model demonstrated that it is not entirely accurate, as some coatings show ∆E₀₀ deviations of up to 10. To improve the model’s applicability, a varnishing coefficient, V, should be introduced, which can reduce ∆E₀₀ variation for each color and substrate. The research showed that a coefficient range from 0.8 to 1.2 yields acceptable results, bringing ∆E₀₀ below 2, thus making the model suitable for coating processes with oil-based and UV coatings.

Among the many types of additive manufacturing, stereolithography (SLA) stands out as one of the most versatile technologies, especially in the production of large prototypes of extremely high surface quality. The basic working principle of this technology has not changed for almost thirty years, but the recent rapid development of the mask-based variant of stereolithographic 3D printing technology (MSLA) has significantly increased its popularity and made it available to a wider range of users. This is especially true for MSLA 3D printers that use liquid crystal displays (LCD) for mask forming. These 3D printers are characterized by large build volume, high resolution and speed of model production, and low price. These factors make them extremely attractive for rapid prototyping or small-scale serial production. However, although they are superior to classical laser-based stereolithography in many technical aspects, their current main drawback is the smaller range of available materials. The development of modern stereolithographic technology has clearly shown that the capabilities of 3D printers themselves are just as important as the materials from which the models are made, the diversity of their mechanical characteristics, available colours, and optical properties. The materials used in all variants of SLA technology are liquid thermoset polymers that are sensitive to UV light (photopolymers). A wide range of areas of application requires a wide range of materials that meet the specific needs of each application. MSLA, as a newer technology, still does not have the same range of materials as 3D printers based on the laser variant of stereolithography. The situation is significantly improving with the increase in the number of available MSLA 3D printers, their popularity, and improved technical characteristics, and it can be said that this is the last step in legitimizing MSLA technology as a competitor to laser stereolithography. The aim of this paper is to analyse the material market for MSLA technology, categorize the supply of materials and objectively compare the available materials with those offered by reputable manufacturers of materials for classic SLA 3D laser printers. Special emphasis is placed on the quality and scope of technical specifications of MSLA materials, which is crucial for their professional use. In addition, the impact of thermoset polymers on user health and the environment is an especially important topic, so an overview of plant-based materials was also made.

Flexo printing or flexography is the most common letterpress printing technique today. Compared to other printing techniques, the advantages of flexographic printing are higher printing speed, low material losses, the possibility of using water-based...

Various parameters and observation conditions contribute to the emergence of color. This phenomenon poses a challenge in modern visual communication systems, which are continuously being enhanced through new insights gained from research into specific psychophysical effects. One such effect is the psychophysical phenomenon of simultaneous contrast. Nearly 90 years ago, Kurt Koffka described one of the earliest illusions related to simultaneous contrast. This study examined the perception of gray tone variations in the Koffka ring against different background color combinations (red, blue, green) displayed on a computer screen. The intensity of the effect was measured using lightness difference ΔL₀₀ across light-, medium-, and dark-gray tones. The results were analyzed using descriptive statistics, while statistically significant differences were determined using the Friedman ANOVA and post hoc Wilcox tests. The strongest visual effect was observed the for dark-gray tones of the Koffka ring on blue/green and red/green backgrounds, indicating that perceptual organization and spatial parameters influence the illusion’s magnitude. The findings suggest important implications for digital media design, where understanding these effects can help avoid unintended color tone distortions caused by simultaneous contrast.

Attracting and retaining the attention of users, or motivating them to use the particular product being the main task of designers in graphic design for all materials, from printed to digital media. It is crucial to select colors that are more appealing to the target audience. The aim of this paper is to explore the differences in color preferences depending on age groups in a nationally representative sample of the Republic of Croatia consisting of 1,000 research participants. For this purpose, a questionnaire was created to collect information on the color preferences of participants, and as a result of this research, it was determined that there are statistically significant differences in the preferences for certain colors depending on the age groups of the participants. It has also been shown that there are both increasing and stable or decreasing trends in color preferences depending on age groups.

In the achromatic White's grid, the grey patches between the grey lines are perceived as darker while the same elements inserted between white lines are perceived lighter than their true measured values. A number of authors attempted to calculate the magnitude and direction of this effect using mathematical models based on multiple spatial filters. This paper uses different mathematical model, based on regression analysis, which has shown itself as an excellent tool for prediction of direction and magnitude of White's effect. The psychophysical visual experiment was conducted on 38 subjects of both genders. The differences in lightness perception ∆L00 were calculated in CIE ∆E_2000 system. This paper determined the functional dependence of White's effect magnitude ∆L00 to the lightness L of rectangular elements in White's achromatic grid. The results gave the square polynomial of very high quality (R2 = 0,974). Regression polynomials were also found. The gave numerical values ∆L00 of difference in perception of left and right elements in comparison to their physical values (left R2 = 0,943, right R2 = 0,938) in dependence to variation of lightness parameter L. Results of the research clearly show the mathematical pattern of White's effect based on the lightness of rectangular elements.