In his preface, Roy S. Berns questions, ‘why another book about color and art?’ and explains the unique insight that he, a colour scientist, can offer the discussion of art display, conservation and documentation; in other words, a practical application of colour theory in a collections setting. Berns introduces his subject with a hypothetical encounter between museum professionals critiquing a recently conserved and re-installed painting, during which the topics of colour perception, visual acuity and art imaging arise. The discussion poses fundamental yet fraught questions, such as when viewing a work of art, how do we know that we are all seeing the same thing? Can an object be recorded or reproduced to a reliable standard, and what does that mean if both the original and reproduction are potentially inconstant?
Color Science is aimed at two primary audiences, museum professionals and students of conservation, which comprises a broad range of disciplines from the sciences and humanities; a variety acknowledged in the structure of the text. The first half of the book explains the fundamentals of colour science and technology while the second outlines practical applications of this field specific to collections care. The division is not stark, however, as each chapter contains several examples, or case studies, in which theory and application merge. In the first chapter, for instance, Berns outlines methods of measuring light and its reflectance off of painted surfaces, explained first with painted swatches and then demonstrated on two paintings by Vincent van Gogh. A reader with little experience wielding a spectrophotometer or shooting multispectral images is, here, introduced to the principles behind these technologies and swiftly acquainted with their merits in identifying specific pigments, gauging how those colorants may have changed and may yet change on a gallery wall. In other words, the reader's journey is punctuated by tangible examples of how colour science impacts (or should impact) the care, presentation and perception of an artwork.
The subjectivity of human vision is a recurring topic in the book. The impact of vision aberrations on colour perception and spatial vision are explained in chapter two through manipulate images, demonstrating how well-known paintings would appear to viewers suffering colour blindness or cataracts, like Claude Monet at the end of his career. Berns illustrates how painters have exploited the characteristics of visual acuity to create convincing artistic effects (the softening of detail to make space recede, the use of brighter hues to make forms emerge). He goes on to suggest how art conservators may use the same theories to strategically supress damages on a painted surface depending on the passages ‘spatial frequency,’ or level of detail, which is subjective based on the viewer and viewing conditions.
The individuality and limitations of even ‘normal’ vision attest to the necessity for standardized, objective methods of characterizing colour. Berns explains how numerical specifications have (in science) replaced the inadequate nomenclature of colour descriptions, highlighting the Munsell and CIELAB systems with generous illustrations of paint swatches and scales, plotted colour measurements and spectra. Though many, the examples are explained concisely and relate to specific works of art, like Monet's Sunrise (Marine) from 1873, which appears chromatically austere but is, as Berns points out, complex and subtle in palette. Such measurements have significant practical applications in conservation science and studio settings, both to calculate lightfastness (or permanence) of newly manufactured colorants and to measure the degree and speed of colour change on extant artworks.
Chapter four focuses on metamorism and colour inconstancy, phenomena in which the appearance of a colour changes due to the light source illuminating it. Bern's introductory scenario in which several museum employees are dissatisfied by the restoration on a painting pertains to a metameric mismatch, probably resulting from the conservator using a light source in the studio that is different to that in the galleries (cool daylight versus warm incandescent, for instance). Berns explains metamorism using paint swatches and examples of typical metameric errors, such as the mismatched ultramarine retouchings over a predominantly Prussian blue passage on Pablo Picasso's The Tradgedy (1903), which match under day light but not under incandescent lights.
The implications of color inconstancy and color rendering on an artwork, even one in good condition, are enormous. The ‘color rendering’ or temperature of any light can skew the appearance of the artist's palette and supress or enhance subtle hue shifts. Berns points out how different a work of art can look in alternative venues (of a travelling exhibit, for example), underlining how disconnected the present viewing conditions of many objects are from where they were conceived or intended to be displayed; a plein air landscape made in glaring sunshine may live in a dim interior, an ecclesiastical object produced for a candle-lit church is now in a bright, naturally-lit gallery.
State of preservation and display are not the only factors influencing the appearance of an artwork on the gallery wall, and in chapter six Berns describes how the physical composition of the paint layer—the technique used to apply the paint, its constituent colorants and surface coatings—can themselves produce optical effects like colour rendering, as one example (if the surface is coated with a yellow varnish or comprises ‘effect pigments’ or fluorescent colorants). Berns describes how different methods of conservation retouching (or inpainting) negotiate the challenge of matching or integrating losses on a paint film that may vary in saturation, hue and thickness. He explains how ‘spatial mixing’ and the nature of human eyesight—its strength at discerning value over hue or colour intensity—can be exploited to this end, and gives a brief but insightful account of how both memetic and discernible retouching methods (like tratteggio) relate to optical mixing, not far removed from Georges Seurat's divisionism.
In the final chapter, Berns describes the processes and challenges of accurate colour reproduction as a tool for both in-house documentation and the dissemination of art images through publication. He explains the complexities of capturing and processing digital images of art objects, and the variety of end-products that can result depending on how and where they are viewed (on a phone screen, computer monitor or printed page). He illustrates how, without standardized guidelines (for the colour calibration of monitors and printers, for example) colour reproductions are susceptible to many of the same anomalies described earlier in the book in the context of art display, like metamorism and colour inconstancy. Berns concludes his text with a discussion on the future of spectral and colorimetric imaging and their potential beyond reproduction and documentation as analytical tools (i.e. for the pigment mapping of paintings).
Berns delivers on his offer at the beginning of the text by providing novel and clear explanations of how colour is perceived in and around an artwork. It provides an excellent introduction for students of conservation or any field dealing with the presentation of art objects. It is also a valuable source for anyone wishing to review or update their understanding of (mostly) painted surfaces, their display and reproduction. The text is intended to be an accessible, go-to source and succeeds, ending with a ‘further reading’ section that lists and briefly reviews related texts. For a topic as broad and subjective as colour and art, Berns presents concise and compelling explanations of how colour impacts the creation, condition, display and documentation of artworks, and is surely valuable addition to any library dealing with those subjects.
