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Oriental China - Single Colour Glazes

( Originally Published 1911 )



FOLLOWING the white in order is the remarkable series of single colour glazes of various hues, be-ginning with the sea-green or Celadon, which is a pale green, or even a greyish green ; and the yellow, especially the Imperial yellow, which is reserved for the Emperors of the Tsing dynasty; camellia-green like the leaves of that plant, painted in proper colours; light brown, a bright colour with quite a metallic lustre, was known as "feuille morte," or dead leaf colour. So copper-reds give various self-colours such as haricot, various flambes, and through a long range it reaches eventually a pure black. Then there are the blues, covering a range no less varied and interesting. Turquoise-blue, a tint which can only be obtained by applying it upon the biscuit china which has already passed through the kiln; the other blues, fouette, souffle, trempe, are brushed on, blown on, or dipped according to the method used in applying the colour glaze. Another way of applying the glaze was by its being powdered on through a fine gauze or dabbed on by means of a wet swab dipped in the colour which was to be used as the single colour glaze.

The purples as glazes are no less rich in variations, and in these tints the Chinese have never been rivalled. These self-colour pieces are decorated with symbolical figures or sacred animals, whilst flowers and inscriptions from the sacred books are found as a decoration in gold, which unfortunately lies upon the glaze and is more or less easily removed by hard wear. Again, similar designs are engraved in the paste, or modelled in relief and painted with such colours as are able to resist the temperature of the furnace. Many pieces have spaces reserved in white for further decoration, and sometimes the decoration is executed in white slip on the paste itself after its first firing has brought it to the biscuit state. These lovely single colour glazes are certainly amongst the finest Oriental specimens of porcelain which are worthy of the collector's attention ; their softness, their brilliancy, their range of colour alike entitle them to a high place in any scheme of decorative treatment either in the home or on the collector's shelves. We call them china or porcelain vases, &c., and in that we are only following the Chinese usage, though the colour glaze is often so thick as to hide the material or body of the paste altogether. The thickness prevents any transmission of light; they have an opaque more or less coarse clay white or red body, and amongst our English products would be classified as stoneware. But the colour is the thing, and here we shall repeat ourselves a little, because it is necessary to really understand not alone what the colours are, but generally the order of their invention. The oldest colour was, as we have said, Celadon, or sea-green, which reached a high state of perfection about 1500. No doubt there are many Celadon pieces of great antiquity still awaiting identification. It was in the Seuen-tih period of the Ming dynasty that this Celadon became a famous product. The porcelain is very thick, and to this thickness it owes its preservation. Like the English ironstone china, it stands hard wear. All the Persians and the Turks value Celadon not for its intrinsic beauty, but because they thought it to be infallible as a test for poison in their food.

The yellow glaze is the colour adopted by the present Tsing dynasty as the Imperial colour. Fine specimens covered with yellow may then be regarded as having been destined principally for the use of the Emperors, but it does not follow that the use of this colour was proscribed in the decoration, either as a yellow or as a partial tint. Blue was one of the highly esteemed colours as well as one of the earliest. We have dealt with blue as an under-glaze decoration. It was not alone used for decorative purposes in drawings of figures, birds, animals, foliage, and landscape, but it was used in various forms as a body colour either on the biscuit itself, before glazing, for with the glaze as a self-colour, as a Celadon, in fact—that is, the blue was applied in the glaze or in the enamel.

We read that in 954 A.D. the Emperor Chin-Tsung ordered some vases to be made which should be " blue as the sky after rain when seen between the clouds," and it is said that his celebrated porcelain was of this blue, fine like a looking-glass, thin as paper, and giving a sound like a musical stone, the only defect being that the feet of the pieces were of a coarse yellow clay. Alas for the romantic story !

The most recent catalogue of the Musee Guimet at Paris, drawn up by the national experts with the assistance of such Chinese experts as were available, states that the story is all a mistake. The word which was translated " blue " should have been trans lated "green," which brings us back again to Celadon.

During the Sung dynasty (960–1279 A.D.) it appears that a fine red was discovered from which porcelain was made resembling chiselled red jade. This may be the celebrated " sang de boeuf," which is red, but, as we have seen, red with qualifications.

The purple or lilac glaze before referred to seems to have been made quite as early as the Sung dynasty, but with this, as with all the other glazes, colour alone is no indication of age.

About the year 1600 there lived that famous potter called Chow, whose fame was obtained by his excellence in skilfully imitating ancient vases. All the records that have come to us show very clearly that from the earliest times the potters were in the habit of copying the works of their predecessors. So well was this continually done that they were able to impose upon the best experts of their own country.

The brown glazes, according to Pere d'Entrecolles in a letter dated 1712, were at that time quite recent inventions, and he applied the same remarks to the coffee-colour glazes. The black glaze has been noted. It has several varieties—the dull black itself, the dull black glazed over with green so as to make a bright black giving a green tinge only at the edges, and the Tsing black, which is an uncommon brilliant black familiarly known as mirror black.

There are many other self-colours or single glazes to which fanciful names are given. We have referred to "clair de lune" and the peach bloom. It is very doubtful whether there is any real value in the names themselves, so we advise our readers to examine specimens in the Museums, when such colours as liver colour, pigeon's blood, crushed strawberry, &c., will be found to be purely arbitrary. Perhaps the widest term applied to these variegated self-colours with a single glaze is splashed or shot silk. These various mottled or splashed glazes are named by the Chinese Yao-pien, by the French flamme or flambe. They have curious yet very beautiful veinings like flames of a fire, hence the name given to them by the French. One colour runs into the other in the most capricious and yet in the most charming manner. The first results were no doubt accidental, but soon experience gave certainty to the master mind of the potter, who was able to define and measure the combination of the various metallic oxides which would give him exactly the colouration he desired. The glaze of these pieces was usually applied upon the dried vessel by dipping or brushing or powdering, or, as some say, by blowing on with a tube. Or, again, it may have been a combination of these processes. The potter now had the means of producing an endless variety of splashing by the proper application of the prepared glazes : of violet and blue ; of turquoise passing into green ; of sea-green, brown, and blue ; of maroon, green, and white ; of, in fact, any colours within the range of his knowledge. He only had to be sure of the furnace. He had to know how his metallic oxides would combine under the action of heat. The glaze upon vessels having intricate designs in relief was applied only after the potter was sure that the pot in its biscuit state was suitable and correct in form. With most ornaments the danger of damage was thus considerably reduced. When the biscuit was with-drawn from the kiln the coloured glaze could be easily applied before the second firing took place. We have noticed that a much lower temperature was needed in the second firing and that the heat of a muffle-kiln would suffice. As in the case of the single glazes, a number of fanciful names have been applied to the ware, such as tiger-skin, iron rust, &c.

CELADON GLAZES. SINGLE COLOURS AND SPLASHED.

The coloured glazes in the pieces of one colour which we have described are called "self" or " whole" colour, and they were applied directly on the dry paste or body so that the whole was fired at one time. The great heat required for this process caused variations in the tints, which were partly due to the running of the glaze itself. Where the glaze lay thickest, the colour would be deepest. Practice led to perfection, so that the Chinese potters acquired skill in using the colour with precision and, further, they were able to extend the range of their operations by using several colours on one piece. Greens of many hues, blues in various shades, all kinds of reds and yellows, purples and browns gave to this class great variety and brilliancy. It must be borne in mind that these coloured glazes were also applied to biscuit porcelain, that is, to white porcelain, without any glaze, which had been fired in the kiln for the purpose of fixing the shape. In this division the paste is generally much thinner than in ordinary pieces of Celadon, and much more elaboration was given to engraved and embossed patterns and to reticulated or pierced work. Moreover, it was easy to leave some parts of the design in untouched biscuit.

Our illustration shows a set of three splashed Vases (two flat-shaped and one hexagonal) painted with enamels of green, yellow, and aubergine, in blotches on a white ground. The handles, which are monsters, are in apple-green. This style of decoration is known as tiger-spotted or splashed. Kang-he period.

The process of decoration by blowing is said to produce a curious colouring. Take, for instance, red blown on blue. Pieces so decorated appear to be covered with a soft violet glaze, but on examination it will be found that the opaque blue is sown all over with minute red rings formed as a network resembling the finest lace. By the use of a simple magnifying-glass these rings can be easily traced. It seems difficult to produce such a marvellous decoration, and yet it is quite simple. The colour blown on that is the red, which is driven with force sufficient to form minute bubbles, which burst by the heat of the kiln, and by their bursting form little rings varying from the size of a pin's head to that of a pea.

It will be well to give just a little time to a summary of the colours which are used on Oriental porcelain of all kinds, first in the under-glaze blue and red, second in the single colour glazes, including all those which are known by the terms splashed, variegated, transmuted, or flamme or flambe. Pre-serving the same order set out in the colour enamels which are used in over-glaze decorations, we find that the blacks, as before stated, were three in number—a common dull black, a mirror or metallic black, and the first of these covered by a thin transparent green glaze, so as to make a shining black. The dull black was produced from manganese which had some impurities in it, whilst the mirror black was made of manganese having cobalt in it mixed with white glaze and an earth containing iron.

The various greens, such as the dark green or gros vert, sea-green or Celadon, apple-green, emerald-green, pea-green, cucumber, and snake-skin were all derived from iron, copper, and a little cobalt.

The many shades of blue dark blue and that peculiar tint known as mazarine, powder blue, sapphire-blue, sky-blue, turquoise-blue, peacock-blue, "clair de lune," and kingfisher-blue—were all secured from cobalt and copper mixed in various pro-portions.

In dealing with the important red family we have to distinguish between the reds derived from copper and those derived from iron and from gold. The range of tints is very extensive. Those derived from copper give the more or less fanciful names of " sang--de-bawl," "sang de poulet," "sang de pigeon," crimson, crushed strawberry, maroon, liver colour, and that curious tint known as peach bloom or peach blow. The reds secured from iron are vermillion, the well-known coral and the tomato tints. From gold, those beautiful shades of colour to which we have referred as being crowning triumphs of the Yung-ching and Keen-lung periods were procured. These, known as ruby, rose, and pink, were really covering a large range of colours from a very faint pink to a red purple.

The yellows have a no less extended range. At the head of the list we find Imperial yellow, then citron or lemon-yellow, eel-skin yellow, straw, canary, mustard, orange, and sulphur-yellow. Thus we see the yellows vary from a faint tinge of that colour to a strong shade which seems to include a little red. All these yellows were derived from antimony, and the variation was largely secured by the addition of iron.

The next class, the brown colour, was derived from iron or from clay in which iron in various pro-portions was present. These browns include various shades such as bronze, chestnut, chamois, chocolate, coffee, " cafe au-Tait," dead leaf—" morte feuille "—old gold.

The colours on English china for the purposes of contrast are given next. They were derived from oxides of various metals in various proportions. The blacks are secured from cobalt, nickel, manganese, iron, and chromium. The greens are variously de-rived ; the yellow-green and the emerald-green are secured from chromium and sodium ; the blue-green or celest from chromium, cobalt, silicon, and zinc; whilst other greens are derived from copper and chromium.

Blues come from cobalt and silicon, except the mat blue, which was procured from cobalt, lime, and zinc. The reds were made from gold and iron, which secured many shades of those colours. The blacks were derived from chromium, iron, and manganese. Another class of European colours—the purples—came from cobalt, chromium, tin, and calcium.



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