Colourimetry is the measurement of the wavelength and the intensity of the electromagnetic radiation in the visible region of the spectrum. At the Grimwade Centre, colour measurements are undertaken primarily to classify colour value and determine fading or deterioration of colour. The process involves analysis over a period of time on the same studied surface to draw comparisons and determine chromatic alteration. A recorded chromatic alteration is an effect of interaction of the environment (location or conservation treatment), thus cause for chromatic alteration can be determined and possibly addressed.
Similarly, gloss measurements can be undertaken over a period of time to determine change in gloss of a surface.