Possible spatial distributions of light incident on a surface.Five basic cesias: black, matte, specular, translucent, and transparent.Diagram of the order system for cesias.One of the possible scales of cesia: from transparent to opaque (different degrees of permeability).
Cesia is the name given to visual appearances related to the perception of different spatial distributions of light. Light radiation that is not absorbed by an object can be reflected or transmitted either diffusely or regularly. These interactions of light with matter are perceived with a greater or lesser degree of gloss (from a mirror to a matte surface, as the extremes), more or less transparent or opaque, translucent or opalescent, and at different levels of darkness (according to the light-dark axis).
This is the same kind of phenomenon that Richard S. Hunter (1969, 1975) calls "geometric attributes of appearance". The advantage is that the concept of cesia encompasses all the involved aspects in a single word, and that all cesias have been organized in a three-dimensional order system according to three axes of variation, similar to color order systems or color models. .
The axes of variation of cesia are: permeability to light (with transparent and opaque as the extremes), diffusivity (with diffuse and regular -or sharp- as the extremes), and darkness (with the poles light and dark -or black).
The term "cesia" was proposed by César Jannello in the 1980s. Jannello died in 1985 without developing the concept in depth (beyond the fact that it refers to qualities or visual appearances such as transparency, gloss, translucency, opacity, etc.), and without devising an order system of cesias. This was the purpose of José Luis Caivano (1991, 1994) since the late eighties and early nineties. Subsequently, the concept of cesia was also taken up and expanded by other authors, who applied it to different fields: Green-Armytage (1993, 2017), Lozano (2006), Jofré (2017), Giglio (2015), to mention just a few. A detailed chronology of publications, as well as antecedents, course syllabi, videos on the subject, and other items, can be found here.
A scale of cesias from specular to matte (different degrees of diffusivity).A scale of cesias from transparent to black (different degrees of darkness).
Giglio, María Paula, ed. 2015. Aportes al estudio de la apariencia visual en contexto de prácticas proyectuales… (Mar del Plata, Argentina: Universidad Nacional de Mar del Plata).
Green-Armytage, Paul. 1993. “Beyond colour”. In: Color 93, Proceedings of the 7th Congress of the AIC, vol. A (Budapest: Hungarian National Color Committee), 155-162.
A gradual variation of cesia from translucent to transparent (varying degrees of diffusivity).Green-Armytage, Paul. 2017. “More than colour – dimensions of light and appearance“. Journal of the AIC 17: 1-27.
Hunter, Richard S. 1969. “Geometric and color attributes of object appearance”. In: AIC Color 69, Proceedings of the First Congress of the International Color Association, Stockholm, 9-13 June 1969, ed. M. Richter (Göttingen: Muster-Schmidt, 1970), vol. 1: 525-529.
Hunter, Richard S. 1975. The measurement of appearance (New York: John Wiley & Sons).
Jannello, César. circa 1980. “La cesía como materia conceptual”, manuscript. Posthumous publication in: Germán Carvajal, Diseño como poética (Buenos Aires: Academia Nacional de Bellas Artes, 2005), 112-115.
Jofré, Varinnia. 2017. Aspectos de la cesía en la imagen artística… (Córdoba, Argentina: Universidad Nacional de Córdoba, Facultad de Artes, doctoral dissertation).
