Abstract This study investigates the electrochemical decolorization of waste acid dye baths and evaluates their potential reuse in subsequent textile dyeing processes. Four different anode materials (iron, aluminum, stainless steel and graphite) were examined to optimize color removal efficiency and assess the influence of electrochemically generated by‐products on dyeing performance. Under optimized operating conditions, aluminum anodes achieved over 90% color removal without generating harmful chlorinated species. However, fabrics dyed in these treated baths exhibited noticeable color differences (ΔE >1), attributed to aluminum's mordanting effect, which enhanced dye uptake particularly for blue dyes. Conversely, iron anodes led to residual metal contamination, while steel and graphite promoted hypochlorite formation, causing dye degradation in subsequent acid dyeing cycles. To mitigate these limitations, iron‐treated baths were alkalized with Na 2 CO 3 and successfully reused in reactive dyeing. Additionally, a membrane‐separated electrochemical system effectively eliminated iron and hypochlorite, enabling the reuse of treated baths in vat dyeing applications. These findings highlight that electrochemical treatment not only facilitates substantial color removal but also supports sustainable water and chemical resource management in textile manufacturing.

Abstract The characteristics of the pigments and the composition of the formulation have a decisive influence on the appearance of coloured plastics, mainly in terms of their reflectance and transmittance. This research presented a novel analytical approach to quantify the optical properties of pigments and predict the appearance of plastics containing these pigments accordingly. Firstly, the Monte Carlo method was employed to characterise the measurement geometry of the spectrophotometer and the light transfer in coloured plastics. Based on this, the paper proposed a method for determining the absorption coefficients and scattering coefficients of the substrate and the pigments according to reflectance and transmittance measurements. To verify the efficacy of the approach, 25 polyethylene‐based samples were prepared. The samples 1–15 were used to determine the optical properties of the respective pigments, and the samples 16–25 to test the predictive capabilities of the model. The result showed that the method can reliably predict the reflectance, transmittance and colour of plastic formulations.

Abstract Understanding the hydrolysis behaviour of reactive dyes is critical for optimising dyeing processes, investigating hydrolysis kinetics and advancing sustainable textile technologies. Conventional analytical methods often fail to distinguish between multiple structurally similar dye forms, limiting kinetic studies. In this study, capillary electrophoresis was used to detect six dye forms of CI Reactive Orange 107 (RO107) and CI Reactive Yellow 201 (RY201). The hydrolysis behaviours were systematically evaluated under varying pH (8.0‐10.0), temperature (40‐70°C) and reaction time (0‐60 minutes). The varying concentrations of different forms indicated that RO107 and RY201 followed a pseudo‐first‐order reaction model, and the hydrolysis rates at 60°C were measured as 1.66 × 10 −2 and 1.64 × 10 −2 min −1 , respectively. Notably, the activated dye forms predominated at lower pH (9.0‐10.0) rather than at the conventionally applied value (pH 11.6) during dyeing. By Keeping hydrolysis below 13%, dye fixation was improved by 15%. Meanwhile, sodium carbonate (Na₂CO₃) dosage was reduced by 47% (from 15.0 to 8.0 g/L) without compromising colour strength. These findings provide a practical and sustainable approach to improving dye utilisation and reducing the environmental impact in textile dyeing.

Abstract A model for directly predicting the actual printed image produced by an ink‐jet printer is proposed. The distribution of ink dots in the printed image is determined solely by the halftone image, while the greyscale values of the sampled pixels are influenced by the blending of multiple ink colours, creating a complex mapping relationship. This paper presents a method to accurately measure ink dot displacement by establishing a deviation transformation relationship for each step of the ink‐jet‐to‐measurement process, enabling precise positioning of the nozzle offset. By combining the ink dot displacement data with the halftone image, an actual ink dot distribution model is constructed. A neural network is employed to fit the mapping between the ink dot distribution of the halftone image and the pixel greyscale values of the printed sample, thereby achieving the prediction of the real printed image. The experimental results demonstrate that the model can accurately predict the post‐press image and reflect the printer defects.

Abstract Vegetable‐tanned calf leathers are highly esteemed for their aesthetic qualities, durability and shape retention, making them particularly suitable for high‐end leather goods such as bags, belts and wallets. Some embossing processes are applied for visual purposes in the production of these leather goods. This study investigates the effects of different vegetable‐tanning agents and varying embossing conditions (temperature and duration) on the shape retention and colour change behaviour of calf leathers. For this purpose, hydrolysable tannins (valonia and chestnut) and condensed tannins (mimosa and quebracho) were incorporated into the tanning process and their effects on the leather's shape retention after embossing and thermal discoloration were analysed. The results provided valuable insights into the role of tannin type in determining post‐emboss leather properties. Colour analysis revealed that both the tanning composition and processing conditions, including temperature and embossing duration, significantly influenced the final appearance of the leather. Notably, elevated embossing temperatures further intensified colour variations. The results of shape retention after embossing indicated that higher temperatures and extended embossing durations improved the durability of embossed patterns, ensuring long‐term stability. These findings contribute to a better understanding of the relationship between type of vegetable tannin and the hot press behaviour of leather, aiding in the selection of suitable tannins for optimising colour stability and shape retention in embossed leathers.

Abstract The use of natural dyes has become increasingly important as a result of their lower environmental impact and health benefits. However, developing eco‐friendly dyeing processes and auxiliary products that maintain high chromatic quality remains a challenge. Natural indigo dye exemplifies this issue, as traditional industrial reduction methods using agents such as sodium dithionite are associated with significant environmental pollution. This study explored the application of fructose as a sustainable reducing agent for dyeing cotton fabrics with indigo extracted from the Indigofera tinctoria plant, adapting an artisanal process to industrial equipment. The most effective method involved a single‐stage vat dyeing process conducted at 60°C for 60 minutes, using a 1‐2‐3 formulation. Results indicated that fructose emerges as an effective and environmentally friendly alternative in an industrial process compared with conventional toxic reducing agents. The study also evaluated the effect of different non‐toxic auxiliary products and mordanting techniques. Pre‐mordanted samples exhibited more saturated colours than post‐mordanted; however, wash fastness results were lower. For example, gallnut used in the pre‐mordanting process produced dark tones but showed noticeable colour change after washing, while post‐mordanted samples achieved higher wash fastness. The integration of diverse auxiliaries in separate dyeing processes expanded the colour spectrum beyond the conventional blue typically associated with indigo dye, introducing a range of unique shades and hues. This study contributes to the recovery of traditional knowledge, incorporating more environmentally friendly products and adapting them to industrial equipment, while exploring a diverse chromatic palette. Such innovation supports fashion designers in creating distinctive and environmentally responsible collections.

Abstract One of the most important analytical techniques in spectral data analysis is derivative spectrophotometry. This technique can increase the signal‐to‐noise ratio in the qualitative and quantitative analysis of multi‐component samples. The appearance of the derivative spectrum, such as height, width and distance between the maximum peaks, changes with the derivative order. Additionally, derivative spectrophotometry has been used to analyse overlapping spectra of multi‐component samples, improve the resolution of overlapping peaks and remove the background as noise. Derivative spectrophotometry has been applied to analyse infrared spectra, fluorescence spectra and ultraviolet–visible spectra data. The five most used methods are peak‐zero, zero‐crossing point, peak‐peak‐ratio, peak‐tangent and ratio of spectra. The concentrations of coloured components in binary and ternary mixtures of dyes were estimated using peak‐zero, zero‐crossing point, peak‐peak‐ratio and ratio of spectra derivative spectrophotometry. The derivative method has been used in several scientific fields, such as characterisation of pigments, characterisation of colourants, identification of pigments in artworks, realistic texture reconstruction of an artwork, characterisation of dyes in ancient purple codices, quantitative analysis of mixed pigments, identification of natural polymers and resins in paintings, determination of food dyes, characterisation of paintings, identification of artists' materials, identification of the natural dyes and identification of pigments. The derivative method has also been applied in the textile industry, including fibre identification, prediction of dye concentrations in solution, analysis of dyes in wastewater, analysis of natural dyes and dyeing recipe prediction.

Abstract This paper investigates the surface properties of 27 wood species exposed to indoor and outdoor weathering agents using above‐ground test equipment for 1 year in Bursa, Turkey. For this purpose, colour changes, surface roughness and chemical composition of wood surfaces were analysed at an interval of 3 months during the exposure period. The results showed that the colour change on the wood surfaces exposed to outdoor weathering was observed during the first 3 months, and that the temperate wood species showed much more surface darkening and colour change compared with tropical wood species. In outdoor weathering, the least colour change was found in wenge as a tropical wood, and in walnut and elm as the temperate species, while the greatest colour change was in ayous and poplar. In the case of indoor weathering, iroko and cherry displayed the least amount of colour change, while the most was seen in wenge and Scots pine. Additionally, surface roughness and cracks increased with weather conditions, especially in outdoor conditions. Fourier Transform–infrared spectra revealed chemical changes, especially in carbonyl and lignin groups. Significant darkening, mould growth and crack formation on the surfaces were observed after the ninth month of outdoor weathering. However, cracks or mould formations were not observed on the samples exposed to indoor weathering; only a slight colour change was common. The study showed that the indoor and outdoor degradation agents, wood species and humidity conditions had an important role in the tested parameters.

Abstract This study examines the effects of starch‐based coating techniques used in electrophotographic printing on colour measurements. After the coating process using five different types of starch (tapioca, corn, wheat, potato, rice), optical and physical tests were performed on the samples, followed by printing using the electrophotographic printing technique. The printing results were then analysed within the colour spectrum, and comparative colour measurements were conducted. The research findings demonstrate that the type of starch used has a significant impact on CMYK (cyan, magenta, yellow, key) colour quality in electrophotographic printing. According to the research results, potato starch performed better than other types of starch in terms of colour harmony, colour saturation, colour consistency, and colour difference. Tapioca and wheat starch were identified as the starch types yielding the worst results.

Abstract Recent global interest in sustainable practices in the textile and fashion industry has inspired stakeholders to readopt natural colourants. However, integrating these practices raises several questions regarding the latest developments in natural colourant and trend forecasting practices in the textile and fashion industry. It also prompts inquiries about how to incorporate the use of natural colourants into current industry, and the role of the trend forecasting industry in this. Colour decisions, first in the fashion design process, are influenced by the designer's creativity, forecasted trends and factory capabilities. A systematic literature review was conducted to examine the latest developments in natural colourants and trend forecasting for the textile and fashion industry. This was compared with a desk‐based review of current trend forecasting practices. Five topics emerged from the examination of the literature of natural colourants: natural colourant sources; colouration technology; the application of natural colourants; culture and tradition; and industrialising natural colourants. Meanwhile, four areas arose from the literature of trend forecasting: technology, process, business and society. The in‐depth analysis of natural colourant literature focused on “industrialising natural colourants” papers and discovered four key themes: industry scalability; consumer behaviour; economic value; and marketing and promotion. Comparison across these reviews identified opportunities for incorporating natural colourants through technology, marketing and education, supported by trend forecasting practices. Further research and significant adjustments in the industry are crucial, either to facilitate the integration of natural colourants into existing systems or to determine whether parallel standards and tools need to be developed.