Application of the nondestructive second derivative spectrophotometry to eliminate the effect of substrate in identification of madder used in Persian carpets

Abstract

The handmade Persian carpet is famous worldwide not only for its elegant design and artistic structure, but also for its brilliant color harmony and incomparable raw materials. Various natural dyes accompanied by different mordants are used on various woolen yarns to obtain a wide range of unrepeatable shades for carpet. In this article, as a first step, the diversity of the undyed woolen yarns used in Persian carpets was statistically investigated by implementation of the Principle Component Analysis. Then the second derivative of Kubelka-Munk function of samples dyed with madder was considered to reach a pattern for identifying madder. The results show that, although the spectral reflectance of different selected woolen yarns has at least 3 dimensions, all derivative curves are qualitatively very similar with the same minimum and maximum peaks at 510 and 605 nm, respectively. The findings are confirmed when various types of madder were used in the dyeing process. As a result, it is shown that the nondestructive derivative spectrophotometry is able to identify madder on alum mordanted woolen yarns used in Persian carpets and to eliminate the effect of substrate. It is a useful technique for preservation, conservation, and dissemination of the Persian carpet. K E Y W O R D S derivative spectrophotometry, Kubelka-Munk function, madder, Persian carpet, woolen yarn 238 | V C 2017 Wiley Periodicals, Inc. wileyonlinelibrary.com/journal/col Color Res Appl. 2018;43:238-246.

Significant Effect of Guest Ions on the Fluorescence Behaviors of Palmatine-Based Supramolecular Systems

“…Color strengths ( K / S ) of the dyed samples were calculated using the Kubelka–Munk function as shown in eq K / S = false( 1 − R false) 2 / 2 R where K is the absorption coefficient, S is the light scattering coefficient, and R is the observed reflectance. Generally, the higher the K / S value, the higher the depth of the color on the fabric. , …”

“…Generally, the higher the K/S value, the higher the depth of the color on the fabric. 54,55 Fastness Test. The wash fastness test of dyed fabrics with PLTbased supramolecular salts was executed by a soaping machine (SW-24E) according to the standard test method ISO 105-B02.…”

Eco-friendly single bath dyeing of wool yarns with extracted cochineal dye: optimization and additives effect

“…Equations ( 1) and (2) were also used to calculate the color strength (k/s) of colored wools. The absorption coefficient is k, the light scattering coefficient is S and the reflection measured by the spectrophotometer is R (Ghanean and Ghanbar Afjeh, 2016). In the experimental design, the sum of k/s was determined and used as the color strength and responsiveness (Burkinshaw, 2016).…”

An improved single constant Kubelka-Munk method for pigment unmixing of Chinese paintings

“…Abu used the single constant KM theory for the hyperspectral images of 'Selden Map of China', transformed the reflectance into absorption and scattering ratio (K/S), and then used the non-negative constrained least squares method to achieve the pigment abundance calculated [10]. Sarvenaz et al used a combination of single constant KM theory and second derivatives to find the abundance of each component dye of the mixed dye color, and finally compared with the real data and found that they were able to accurately estimate the abundance [11]. With the development of deep learning, Rohani N combined single constant KM theory and deep neural networks to achieve the solution of pigment abundance, and found that the proposed algorithm of reconstructing the error of different colors can accurately estimate the pigment abundance effectively [12].…”