Changes in pigments, whether used pure or admixed, can alter the appearance of a painting significantly; consequently, the identification and state of degradation of colourants is of fundamental interest, since it provides critical information about the artists' aesthetic perspective, conceptions and choices, and how the work has changed over time.
Food dyes are the most controversial but essential group of food additives as they are unavoidable colourants of foods, cosmetics and drugs for aesthetic reasons (Piccin et al. 2009; Wrolstad and Culver 2012).
McCabe's case is the latest in a series of recent news reports linking the use of hair colourant to serious anaphylactic reactions.
One of the components contains a blue food colourant, so there is an intraoperative visualisation of where SprayShield® was used [ 50, 51].
Match the colour of the rest of the leather then apply a leather colourant to the top layer of filler with a cotton wool bud.
The levels of iron, alumina, manganese and magnesia in sample JK26 are similar to those in the non-cobalt coloured Jebel Khalid glasses suggesting that the source of colourant was not cobaltiferous alum.
Other green to pale greenish or pale bluish glasses do not contain a significant quantity of this colourant, and derive their colour from iron, introduced as an impurity in the glass raw materials in similar concentrations in all samples [2: pp. 35, 48, 143, 61: p. 180T, 66: pp. 91, 163 164].
I had been dyeing my hair for almost 20 years, with the same popular brand of colourant, and had never experienced anything more than mild itching and slight redness around the hairline.
The twigs become encrusted with a reddish, bumpy, and glossy resin that is processed to extract the red colourant; lighter grades of the resin are used as the basis for shellac, and was used as a silk dye in India and imported to Spain since the early 13th century.
