Cerulean blue has a neutral blue hue that when viewed under incandescent light is more or less greenish-blue. Grinding it for artists' use in oil will require 35 percent dry pigment to 65 percent by weight of poppy seed or walnut oil, either of which is preferred by some artists to linseed oil. It has been noted in some manuals that the pigment works better as a watercolor than it does in oil, and is highly valued on that account among moist colors used by artists. Oil Absorption and GrindingĬerulean blue absorbs a moderately high amount of oil about 55 grams of linseed oil per 100 grams of pigment to make a paste. Differences in how the pigment is ground and mixed can lead to considerable differences in its appearance. In oil-based paint, Cerulean blue is a semi-transparent pigment with moderate tinting strength. Differences in how the pigment is ground and mixed lead to considerable differences in its performance. Although pigment particles are very fine, they flocculate, giving a grainy appearance in watercolor. When it dries, it appears lighter and less saturated. In most water-based paint, Cerulean blue is a semi-transparent pigment with moderate tinting strength. Cobalt Blue Pigment FamilyĪll cobalt blue pigments are chemically inert, absolutely insoluble, have good hiding power and excellent heat stability, and show very good lightfastness and weather resistance. The mixture is thoroughly washed, mixed with silica and calcium sulfate, and heated. Cerulean blue is cobaltous stannate and is made by mixing cobaltous chloride with potassium stannate. The constitution may additionally have Al 2O 3, Fe 2O 3, and/or NiO as modifiers that are used to adjust color hue and other properties that may be needed in specific applications. They are homogeneously, ionically entwined forming a crystalline spinel-type matrix. nSnO 2) is an inorganic pigment that is the reaction product of calcining a mixture of different amounts of both cobalt (II) oxide and tin (III) oxide. SourceĬerulean blue or cobalt tin blue (CoO. It suffers less from metameric effects than the other cobalt blues. Cerulean blue is used in both oil and watercolor, it covers well but is not strongly staining. Scott, Modern Water-Colour Pigments 1887, p. Unless used with care it is apt to produce a chalky effect, and it washes in a very indifferent manner” (Taylor, J. He comments, “By daylight it is a light greenish-grey blue with little depth or richness of colour. In 1887 the author of a Winsor and Newton publication was hardly enthusiastic about the pigment. The Artists Handbook of Materials and Techniques Edit. The compound was known from the early 19th century, but was first introduced as an artist’s pigment by George Rowney: Gettens and Stout say that date was 1860, but Mayer gives it as 1870 (Mayer, R. In oil, it was particularly valuable to landscape painters for skies. It was not recommended for use in watercolor painting because of chalkiness in washes. Cerulean blue has a fairly true blue (not greenish or purplish) but it doesn't have the opacity or richness of cobalt blue. Very stable and lightfast greenish-blue with limited hiding power. The name “Cerulean blue” comes from Latin caeruleus meaning dark blue caelum which in turn probably derives from caelulum, diminutive of caelum, “heaven, sky”.Ĭerulean blue is cobalt stannate that was introduced as a pigment in the 1860s. Conforms to ASTM D-4236.įor a detailed explanation of the terms in the table above, please visit Composition and Permanence. Do this by avoiding ingestion, excessive skin contact, and inhalation of spraying mists, sanding dust, and vapors from heating. Always protect yourself against potentially unknown chronic hazards of this and other chemical products by keeping them out of your body. There are no acute or known chronic health hazards associated with the anticipated use of this product (most chemicals are not fully tested for chronic toxicity). This pigment is very easily dispersible, does not need grinding for dispersion, and can simply be stirred using most laboratory and production equipment to achieve full dispersion. They have excellent chemical and heat stability and can be used in chemically aggressive environments and exterior durable applications without color fade. Cobalt blue pigments are the most durable blue pigments commercially available. Cerulean blue is made by roasting cobalt and tin oxides. Rublev Colours Cerulean Blue pigment is composed of cobalt stannate.
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