This paper reports the impact of screen-printed PEDOT:PSS conductive ink on the optical properties of polyester fabric and colourimetric properties of yellow screen printing ink printed in a different number of layers. Yellow was chosen as one of four process colours which should theoretically suffer the most prominent changes from PEDOT:PSS overprinting. The study found that PEDOT:PSS ink significantly impacts the optical properties of the fabric and yellow ink, especially regarding the lightness and b-coordinate of the yellow ink. The acid treatment of samples, to increase PEDOT:PSS conductivity, also affected the optical characteristics through partial neutralization of the changes in the b-coordinate, especially when the sample was printed with a larger number of layers of the yellow ink and a smaller number of layers of PEDOT:PSS ink. Samples with two layers of yellow and one layer of PEDOT:PSS ink showed good conductivity results even without acid treatment, while the base colour appeared slightly darker. This change in the lightness can be compensated to some extent, proving that the aforementioned combination of PEDOT:PSS and base ink layers are the best when aspects, such as optical characteristics, conductivity, the complexity of production, production time, and limitations of the use of substrate materials are taken into account. This study provides useful insights for optimizing the printing process of PEDOT:PSS conductive inks over screen printed fabrics for various applications, including wearable electronics and smart textiles.

It is known that gloss has a significant impact on colour measurement. The UV varnish used for surface finishing, spot effects, as well as special effects, such as 3D effects and formation of Braille, has a pronounced gloss effect. In this work, a comparison of the spectrophotometer measurement geometry influence on the colour measurement of an unprinted PVC sample covered with UV varnish was done. UV varnish was applied successively in layers, and patches with different number of varnish layers, from 1 to 12, were formed. Two spectrophotometers with different measurement geometries were used for the measurement: Konica Minolta CM-2600d with d/8 measurement geometry, with spectral reflection included and excluded, and different measurement aperture 3 and 8 mm, and X-Rite eXact with 45/0 measurement geometry. By comparing the measurements, it was estab-lished that there is a significant difference in the measured values between different measuring device geometries on the given samples, and that the number of UV varnish layers has a significant influence on this differenc

Many recent research has focused on graphic design and shape of the packaging, and their effects on the customer's decision-making process as two separate categories. Since the shape of the packaging along with the graphic design plays an important role in the visual appearance of the packaging and attracts the customer's attention, the main objective of this research was to find out which packaging shapes and graphic elements customers find most attractive, as well as to understand the general opinion of customers about the influence of packaging aesthetics on their decision-making process when purchasing a product. Methodology of this research was conducted in two stages, from which the first one included creating three different graphic design solutions combined with three shape categories, and three variations of added value, for the same food packaging. The second part of the research covered an online questionnaire, in which a group of 50 people participated. This questionnaire focused on three variables: graphic design of the packaging, packaging shape and it’s added value. These variables were evaluated using the Likert scale. Through the questionnaire, participants were asked to answer general questions about the impact of the packaging visual appearance and added value, on their decision-making process when buying a product, as well as to choose the most appealing packaging between the given options. The research results showed that customers preferred non-standard packaging shapes and simple graphic design, as well as packaging with added value. The results of this research prove that the aesthetics of packaging has an impact on the customer's perception of a product, which means that packaging plays an important role in product marketing.