Marbling is similar to cooking, it is impossible to prescribe an exact recipe. Everyone has his own mixture of colours and patterns that he wishes to reflect to the world. The process of marbling begins with dissolving gum tragacanth in water. This water is then poured into the tank. Then the dyes to be used are emptied from the jars one after another using the brushes and are sprinkled onto the solution.
Each of the dyes added, strewn one onto the other, produce attractive figures. A sheet of paper of the required size is placed on the marbling container and the image created by the dyes on the surface of the waters is impregnated on the papers. The paper is then removed and left to dry. The tank is then ready for another marbling operation.
Marbling results from the simultaneous operation of many accurate balances. Purity and application rules must be strictly observed. The density of the gummed water and the relationships between the water and the dye, the dye and the tensioning agent (gall), and the quantity of gall in the dye are all very important. It may take some time to establish the right delicate balance. But when everything is ready, marbling is easily and quickly performed. This property of the marbling makes it very suitable for a 'therapy'.
Materials used in Marbling Art Ebru
Gum Tragacanth (kitre): Gum tragacanth is obtained from the trunk of a thorny plant which grows naturally in the Anatolian, Persian and Turkistan mountains and is called "gaven". The sap oozing from scratches made on the branches later dries and solidifies into bone white colour pieces. It is dropped in water with very low hardness at the rate of 20-40 grams/3 litres and kept for a while. The gum having dissolved completely is filtered through a cloth bag and poured into the basin. It should have the density of buttermilk. About 1 part of gum tragacanth should be added to 100 parts of water and the liquid should be left for at least one night to allow the gum to dissolve. The liquid then should be strained through a cloth and poured into the marbling tank. If it is too thick, some water may be added to thin it. The degree of viscosity should vary according to the darkness or lightness of the colours being used. Gum tragacanth keeps the dyes on the surface by giving body to the water and because of its transparent slightly sticky nature it forms a lacquer over the dyes.
Gum tragacanth is widely used as herbal medicine (in throat and stomach diseases) and in the cosmetic and textile industry.
Dyes: The colours used in marbling are "mineral dyes", as they are called in the classical method, and they are obtained from natural metal oxides. There are also a few vegetable dyes. Anatolia is a very rich country in respect of such natural dyes.
Many kinds of soil can be first made into mud then filtered and crushed to form a dye. The dyes are ground into fine powder by crushing them on marble with a specially shaped mortar pestle made of marble. Each of these powdered dyes is placed in a separate glass jar to which a small quantity of water and five to ten drops of ox bile are added.
Paintbrushes: Marbling requires the use of special, coarse horsehair bound around a rose tree stick in a manner to form a circumference with a hollow centre. Rose tree is preferred because it prevents mould. Brushes of different thickness and length enable application and control of the dye. The length and degree of packing among the brush bristles is important.
Basin or Tanks: Tanks should be made of pinewood, zinc or galvanized metal and they generally measure 35 by 50 centimetres or 17.5 by 25 centimetres, larger than the paper size (to offset the dilatation of paper when wet). These tanks have a depth of about 5 to 6 centimetres (2 to 2.5 inches). Tanks made of other materials hinder the dispersion of the dyes.
Water: Water should be calcium free to avoid fading and ozone free to keep the gum tragacanth from foaming and deteriorating. It is preferable without hardness. The ideal is distilled water. In older times, rainwater was preferred but because of acid rain in our times it is no longer advisable.
Paper: Marbling can be done on all types of paper, cloth, wood, veneers, ceramics, pottery and glass using only mineral dyes and natural indigo and without additives. But the ideal paper is the one that is handmade, has a high absorption capacity and is acid-free. On account of its rarity and high cost we do not advise it for beginners. Instead any kind of non-glossy paper may be used.
Bile (Ox-Gall): This is the most important material for marbling. A marbling artisan must understand well what is gall and what are its functions. It can be said that the secret of the marbling lies in the gall. Because of these solvent-like and adhesive- like properties, the gall that is used in marbling prevents the dye from remaining on the surface of the gum tragacanth solution and avoids dispersion and colour mixing.
Different types of galls are used to achieve different results. Ox gall allows the dyes to spread; turbot bile is used to achieve a "sandy" pattern whereas chicken bile stabilizes the white areas achieved with naphtha. Boiled bile will lose its properties.
Therefore either fresh or pasteurized bile should be used. Its main functions are:
a. To ensure surface tension so that dye spreads over the water surface otherwise it sinks;
b. To prevent mixing of dyes. For instance when blue and yellow are simultaneously applied and mixed up as much as possible, green never appears;
c. To assist dye fixation on the paper;
d. To give different shades of the same colour and different size of patterns.
The Art Of Marbling.
Ebru: Turkish Marbling.
Ebru l'art du papier marbré.
Silver, Joel, Marbled paper, November/December 2005.