Colorcurve and coloroid notations for the OSA-UCS atlas samples

Colorcurve (D65/1964) and Coloroid (C/1931) notations of the 558 OSA-UCS atlas samples are presented in two tables. One table provides the Colorcurve and Coloroid notations for the 424 regular samples; the other for the 134 near-neutral (half-step) samples. Colorcurve notations are derived from the OSA-UCS aim points, and Coloroid notations are derived from colorimetric data of the OSA-UCS samples contained in MacAdam's copy of the OSA-UCS colour atlas.     

Munsell and Ostwald colour spaces: A comparison in the field of hair colouring

Colour science has had a very long history, dotted over the millennia with many contributions from the most diverse fields of human knowledge. At the beginning of the 20th century, Albert Henry Munsell, an artist formally trained in academia, and Friedrich Wilhelm Ostwald, Nobel prize for chemistry in 1909 and amateur painter, each envisioned and developed a colour system with a related colour atlas. Both authors recognized the importance of the visual relationship between colours, which they conceived as sensations stemming from, but not merely confined to, pigments and light. We hereby describe the salient features of these colour spaces, their strengths and weaknesses, the authors' analogy of intents and divergence in execution. The contribution of this paper is a discussion on how these are employed both in Italian educational facilities, and salon practice, as well as a suggestion about their use within the industry of human hair cosmetics.     

Accuracy of the NCS Atlas Samples

This article describes a further investigation into the accuracy of the samples that comprise the NCS colour atlas. Earlier research has demonstrated that the NCS atlas samples are, on average, more inaccurate than the samples that comprise other comparable colour atlases. The present work identifies areas of the NCS colour atlas containing coloured samples that significantly deviate from their intended aim points.     

Printing the light

This paper explores the relationship between additive and subtractive mixing for colour printing. Using Spectraval mica pigments (Merck)—marketed as RGB pigments—colour is generated by selective reflection and prints are based on additive colour mixing principles, that when printed onto black paper, create white and a range of colours. Although currently used mostly for decorative effects, they can be the basis of additive 'process' inks, that present new opportunities for and challenges to traditional print markets. The viewing angle dependency of their selective reflection favours applications in security printing similar to the holograms on bank cards for example. Traditional measurement and modelling methods are difficult to apply due to the layering and irregular dispersion of pigments.     

Polymer‐ and wax‐based monoconcentrate predispersed pigments in the colouring of plastics

Over the past few decades, masterbatch production has been increasing year by year. Pigments are used primarily in masterbatches because of their ability to impart colour or opacity to a matrix. The effectiveness of pigments depends not only on their intrinsic ability to absorb or scatter light, but also, importantly, on the dispersiblity and distribution of the pigments that can be achieved in plastics. Nowadays, stringent environmental as well as excellent quality controls are making inevitable the use of non‐dusty monoconcentrated predispersed pigments for the production of masterbatches for the colouring of plastics. Commercially, for the most part, two types of monoconcentrated predispersed pigments are being used for the colouring of thermoplastic masterbatches. These are polymer‐ and wax‐based predispersed pigments. This study has been undertaken to provide a comparison of the colouring properties of polymer‐ and wax‐based monoconcentrated predispersed pigments. Four commercially used organic pigments have been selected. Both types of monoconcentrate predispersed pigments have been developed on a co‐rotating twin‐screw compounding extruder with a length/diameter ratio of 44. A detailed analysis on the comparison of the colouring properties is presented. Results indicate that good colour properties are achieved when operating conditions are optimised.     

Michel‐Eugène Chevreul: From laws and principles to the production of colour plates

Michel‐Eugène Chevreul (1786–1889) did major scientific work in the fields of chemistry and colour and pioneered the study of simultaneous contrast. His book De la loi du contraste simultané des couleurs (The Principles of Harmony and Contrast of Colours) was published in 1839. Here, his studies pertained to simultaneous contrast, when two or more colours seen contiguously are influenced in brightness and/or in hue, and on successive contrast, when afterimages modify colour perception. He also investigated the mixed contrast that appeared in tapestries in which a mixture of colours was obtained by the plying of yarn or by hatching. Later, he reported on the influence exerted on vision by coloured objects in circular motion around an axis perpendicular to their plane (1879). Many examples and numerous experimental checks documented in his books supported his demonstration of contrast. Of particular interest are the colour plates attached to the books. Another significant work by Chevreul was a three‐dimensional colour classification system (1864), after which he manufactured a colour atlas showing colour circles and monochrome lightness scales. Data are presented from recent measurements of Chevreul's atlas circles and plates, and there is a discussion of his choice of complementary colours. © 2002 John Wiley & Sons, Inc. Col Res Appl, 27, 4–14, 2002     

Spectral studies of lithol red pigments

The origins of the colour changes in different metal salts of Lithol Red pigments have been investigated by spectral methods. The results indicate that all the examined pigments exist, both in solution and in the crystal state, in the hydrazone form. All the products had very similar spectra in solution. In the crystal state intermolecular interactions influenced by the crystal structure and by the size of the metal cation may be the factors which cause the observed colour of the pigments.     

变色颜料

变色颜料严格地讲,应属于无机颜料,但许多变色颜料都是和传统的有机颜料复合使用,使传统的颜料、涂料工业以及防伪油墨等受到了极大的挑战,充满了商机。本文综述了变色颜料的最新发展,重点介绍了变色颜料的结构、光可变机理、随视角变化的CIELAB色彩空间坐标图及加工工艺。     

Chromic textiles: Colour fastness properties and irreversible colour change behaviour of textiles screen printed with thermochromic,photochromic and hydrochromic colourants

The objective of this work was to study how ultraviolet (UV) light exposure, washing and rubbing can influence colour and dynamic qualities of chromic textiles, and to explore how the results attained can be applied by designers for the development of colour changing palettes. The experimental work was conducted with 74% polyamide and 26% elastane elastics screen printed with thermochromic, photochromic and hydrochromic pigments in diverse colours. Initially, colourfastness properties of each pigment type versus colour were assessed. Although washing and rubbing can interfere in samples' colours by becoming lighter at different degrees, the results attained highlight the poor stability to lighting of thermochromic and photochromic pigments, which also present changes between hues along exposure time. For conventional textile applications, poor colour fastness commonly represents a limitation. This work proposes that the way textile colours and behaviour are permanently affected by the studied conditions can be interpreted as a creative variable in the design process. Research samples with a combination of pigments were developed and tested with a combination of cycles of different fastness tests, namely one washing cycle for every 4 h of UV light exposure, totalling 48 h and 12 washing cycles. Results demonstrate the possibility of creating interactive surfaces capable of displaying a wide range of colours that evolve to static within different hues, over stimuli conditions.     

Minimisation of toxicity in nickel ferrite black pigment

Abstract

Black ceramic pigments are usually prepared from a mixture of transition metal oxides, including toxic and hazardous elements such as Ni, Co, Cr, and Mn. Spinel type black ceramic pigments based on Ni(Fe,Cr)₂O₄ prepared by a ceramic method have been optimised to reduce toxic and hazardous components. Ni (an A1 carcinogen as classified by ACGIH)has been partially substituted by inert elements such as Mg and Zn and the content of Cr (an A1 carcinogen in hexavalent form) has been minimised, to obtain a black ceramic pigment in which the important properties (colour and stability) are maintained. The black pigments obtained have been glazed and compared with commercial pigments. While maintaining adequate colouring properties, the concentration of toxic elements in the composition has been reduced.     

Evolution and human's attraction and reaction to colour: Food and health

For continued good health, we are urged to design our meals around the colours of the rainbow. To answer the question “Why?” requires consideration of two evolutionary stories. These broadly are natural evolution, and evolution driven by the activities of human beings. For the first, we need to go back to the start of life on earth and think about pigments rather than colour. There are two major pigment families, carotenoids and those based on the porphyrin ring, without both of which life on earth would not exist, and which still play major roles in our make‐up and well‐being. Other pigments, edible and poisonous evolved as pressures on plant life increased through predation and their own need for survival. The second story commenced with the arrival of human beings and their eventual ability to control fire leading to development of food preservation, processing and more recently, ultraprocessing. The rainbow rule does not apply to such foods in which colour is an indicator of process. Heavily processed foods include use of coloured, cheap, poor quality, and unhealthy ingredients contributing to the present health crisis. For this intervention by humans we must switch from consideration of pigment to that of colour, because it is colour that is a major factor in our selection of the food we eat today.     

通用水性色浆体系性能影响因素探讨

相对于颜料,通用水性色浆具有添加方便、容易分散、环保等优势。通过测试色浆的细度、贮存稳定性以及与涂料的相容性等,讨论了水性无树脂色浆制备过程中颜料、分散剂、防沉剂等对色浆性能的影响。     

Production and characterisation of iron-chromium pigments and their interactions with transparent glazes

In this study, production and characterisation of pigments by using less expensive raw materials such as limonite and chromite was undertaken. The resulting pigments were characterised by using X-ray diffraction (XRD) and UV-Vis spectrophotometer. The colour of glazed tiles containing 3 wt.% pigment change from dark brown to light brown depending on the calcination temperature and limonite content. With pigments prepared with 50% limonite content calcined at 1250 °C, the chocolate brown colour was obtained corresponding to the commercial brown pigments. An iron-chromium black pigment was synthesised from a mixture of pure chromium (III) oxide (Cr₂O₃) and iron (III) oxide (Fe₂O₃) powders and was used to determine possible interactions between a pigment and a transparent glaze. The interactions were studied using a scanning electron microscope (SEM) attached with an energy dispersive X-ray spectrometer (EDX). The results showed that black pigment particles give brown colour to the glaze. EDX analysis on pigment crystals embedded in the glaze clearly showed that Zn and Mg diffused into pigment crystals and caused a change of colour from black to brown.     

Influence of crystallinity on chromatic parameters of enamels coloured with malayaite pink pigments

Chromium-doped malayaite ceramic pigments, CaSnSiO₅:Cr were obtained by solid state reaction using CaCO₃, SnO_2, SiO₂ and PbCrO₄ as precursors. The synthesis process was studied by means of thermal analysis and mass spectroscopy, the results evidencing the volatilization of carbon dioxide and lead in a large temperature range. The major aim of the study was to evaluate the dependence of the pigment colour and crystallinity from the soaking time at a maximum synthesis temperature fixed at 1400 °C. X-ray diffraction data indicate a nearly linear tendency of crystallinity increase with increasing soaking time. The colour of glazes prepared with the pigments, which was monitored by measuring their chromatic coordinates, presents a clear tendency of improvement with increasing crystallinity. This was interpreted in terms of decreasing solubility of the pigments as their crystallite size is increased. SEM and EDX studies confirm that hypothesis, evidencing very small dissolution of the highly crystallized pigments in the glaze.     

Self-stratifying coatings containing barrier and active anticorrosive pigments

The influence of decorative and anticorrosive pigments on the distribution of pigments and protective properties of self-stratifying epoxy/acrylic coating systems was investigated. The separation of pigments was determined basing on their properties and the type of additives used and was expressed as a factor determining the separation of the pigments between the upper and bottom layer. The pigment distribution coefficient was calculated basing on the colour difference between the upper and bottom layer as well as by means of the XRF method.     

MIO与CMIO颜料的特性与合成

介绍了云母氧化铁与彩色云母氧化铁分别作为防锈颜料和珠光颜料的性能及合成方法，探讨了彩色云母氧化铁的应用前景。     

Effect of particle size on pigments colour

The historical pigments, contrary to modern ones, are not constituted by particles having all the same size and this influences the colour of the paint layers. The hiding power and colouring power of a pigment depends, in fact, on its particle size. The aim of this study was to evaluate the influence of particle size on optical characterization of paintings in terms of reflection of light and related colour specification. Starting from the qualitative observation, we have attempted to quantify the pigments colour variations induced by grinding and then attributable to granularity. Powdered pigments of principal colours have been selected in specific particle size range by mechanical sieving. The measurements were performed both on pigment pellets and on paintings realized with binder casein. All samples were characterized by an optical and colorimetric point of view through spectrophotometric analysis and for the surface morphological observation through scanning electron microscopy. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 236–243, 2017     

色酚AS偶氮颜料（一）

色酚AS类颜料是由2-羟基-3-萘酰胺化合物作为偶合组分与取代基芳胺重氮盐偶合制得的偶氮颜料,主要给出红色谱,颜料分子中因含有甲酰氮基（-CONH-）具有良好的耐溶剂性能.文中介绍色酚AS偶氮颜料的发展历史、化学性质及生产、性能、应用,并介绍了目前市场上的二组商用色酚AS偶氮颜料,色酚AS偶氮颜料中红112、146以及170在传统工业领域的红色谱中具有相当的市场份额.     

Colour and colour vision of creatures great and small

Today the mechanisms of human colour vision are well understood because of the detailed communication feedback possible in experimental studies. The situation with other species in the animal kingdom is less easy to investigate and understand. In the present review, examples of the colour and colour vision of various animal species are described, selected mainly because they are particularly interesting and indeed colourful. The chemical structures and the relationships of the natural pigments involved also receive attention. Despite many decades of vision research, many aspects of colour vision remain unclear. Nevertheless increasing knowledge in all these fields may someday help to elucidate the neurological pathways underlying other animals' colour vision to the same extent as is at present known for human vision.     

Effect of Er3+ substitution on the quality of Mg–Fe spinel pigments

Inorganic pigments containing erbium cations and based on the spinel structure of MgFe₂O₄ were prepared. This type of spinel compound provides pigments of red to brown colour; an increase in the content of trivalent erbium cations results in pigments of a light brown hue. The pigments displayed good resistance to sunlight but this was reduced as the content of erbium increased. Pigments prepared using mechanoactivation possessed good resistance to sunlight over a range of erbium cation content.