Post by – Gautam Shah



Oil bound distemper is one of the most common and oldest oil and water dispersion coating system for masonry surfaces. These emulsion-distempers, are better then Calcimine. This is now outdated technology in many parts of the world. Such  paint, however, are produced and used in many developing countries of the world. It is rather easy to procure the raw materials and produce it with very little use of power, tools or equipments. It is comparatively an eco-friendly system, as it has very small amounts toxic materials or petroleum solvents.

The Oil Bound Distempers are made by emulsifying Bodied drying oils or their alkyds with water in the presence of casein, glue dextrine (which also provide the film).

Traditionally distemper or glue based interior paints were made with either animal hide glue or rabbit skin glue. Glue is heated and mixed with a paste of slaked (water soaked) whiting or calcium carbonate and pigment paste. Glue-based distempers were preferred as its pH was compatible with alkaline masonry and plaster surfaces. Oil paints were difficult and costly to produce, and peeled of from the alkaline surfaces. Distemper are water based systems and so dry out very fast, so preferred for not only interior surfaces but wood, paper and canvas  surfaces in art works. These are used for restoration of architectural heritage of 19th C later periods.

Distemper on palm leaf Buddhist art 12th C

Water is mixed with casein, glue or dextrine and an alkali, such as lime or soap, is combined with the oil component such as the Bodied drying oils or their alkyds. The mixture is heavily agitated and emulsion is formed. Stabilizers (to preserve the state of suspension) and antibacterial agents are then incorporated for prolonged storage life.

The film is first formed due to evaporation of water, The Glue component, on removal of water provides the binding. The oil component then forms a latticed (porous) film on the top part of the surface. Oil oxidation of the oils may take more then 24 hours. The hardened film becomes moderately wipe-able or the commercial signature ‘washable distemper’ (compared with the Calcimine) .

After two or three coats over a period of 5/10 years, repainting becomes difficult. Fresh coat of OBD over old OBD softens it to some extent, and causes it to swell. The strength of coating is less than that of oil paint. During drying, the OBD film shrinks substantially and exerts a considerable pull over the underlying film.

Raphael The Miraculous Draught of Fishes 1515

Distempers are essentially masonry coatings so contain substantial amounts of, extenders as bodying agent. Extenders are low refractivity white mineral powders like Calcium Carbonate, Barytes, talc, etc. Extenders also reduce the need for White pigments (high refractivity powders) such Zinc Oxide, Titanium Dioxide. etc.


Oil Bound Distempers do not have rich hue colours. Majority of commercial shades are of pastel variety(white added tones). Due to a low amount of Oil or related constituents in the emulsion the finish is low gloss or dull (low sheen or matt).

Oil bound-distempers or OBD, are sold in viscous paste form, reducible with plain water or special thinning liquids, to brush-able viscosity. Proprietary thinning compounds are very light <oil in water> emulsions, often with additives such as silicone oil, stabilizers, plasticizer, and antibacterial agents and occasionally organic solvents.

MiG-3 aircraft in winter Washed out distemper as a camouflage World_War II

Water-based latex paints

Oil bound distempers are difficult for re-coating purposes. Their water resistance is also not very good. So some time in 1950-1960s a range of Vinyl-based emulsion polymers began to replace the caseins and natural gums -the most moisture susceptible components. Later even the oils were eliminated. Resultant new product was known as the water-based latex paint. Latex is a term more used in USA, where all plastic emulsion products were also known as Latex systems. In most other countries Plastic emulsion paint is popular term.

Dieric Bouts The Entombment Artron

Vinyl-based emulsion coating systems had good binding and slightly better water resistance, but their UV (solar light) resistance was poor. It made the film tacky -attracted moisture (on the breakdown of polymer chain). The product soon saw a replacement with Acrylic Polymer-based emulsions. Both the products were marketed as Latex or Plastic Distempers, fully washable distempers or synthetic distempers.

Pieter_Janssens_Elinga Room_in_a_Dutch_House

Water bound systems are favoured by films, drama and TV scenographers for set making and and scenery backdrops, for three reasons, Fast drying quality, matt (non reflective) surface and high level of opacity (presence of whiting offers better hiding power).





Distemper is a term used for older generation of water-based coating systems, which have had varied formulation in different regions and ages. These have been mainly masonry and plaster surface coatings but occasionally also used for wood surfaces. These were devised to supplant or add upon the vast varieties of coloured lime and chalk finishes. Calcimine (or Kalsomine) is made of Calcium Carbonate, a colourant compound and a binder. Binder was necessary as Calcium Carbonate (unlike Calcium Hydrate CaOH2) has no surface binding qualities.


Dry distemper is made with Calcium Carbonate, Colourant and glue powder (plant gum). A calcium carbonate helps in grinding, finely disperse the colourant and eliminates the flocculation of the pigment. During the coating process Calcium Carbonate provides body to the paint. As the plant gum is hygroscopic, so absorbs moisture, and makes its storage and grinding a difficult proposition. Excessive gum in the mix leads to cracking and peeling from the ground, whereas too little gum or binder makes the surface powdery or friable, and deficient in strength. In adverse climatic conditions (moist) wash-off or bleaching is very common. Distemper coatings being water-based system dry-out to a slightly lighter shade then their wet or freshly applied state.


For application the Dry Distempers are mixed with plain water or thin lime water. In the latter case it is almost a coloured lime-wash. The fouling of plant gum is very common with such coatings, and for that reason copper sulphate and other anti-fouling agents are added.


Calcimine system is made from natural materials each of which is non toxic. The coating system is ecologically a safe formulation during application and later in disposal of it. It is a sustainable system. The Calcimine coating is water-based, and its constituents do not convert themselves into a different product, so the system can be called a non-convertible system (a system that can be recovered to its original form), a very essential factor for its suitability as a conservation and preservation product.


Dry Distempers are also called Calcimine or Kalsomine, due to the main constituent the Calcium Carbonate. This is also called stucco paint because it is used for masonry and Plaster of Paris surfaces. Dry distemper or Calcimine coatings are used for interior surfaces, ceilings, temporary works like exhibition stands, stage settings, scenery painting, Rangoli and temporary sign boards.


Many Medieval and Renaissance painters have used distemper painting rather than oil paint for some of their works. The earliest paintings on canvas were mostly in distemper. Distempers for art works were also prepared with variety of starches and animal gums. Paintings made with distemper as medium are highly susceptible to weather and bi-degradation.


Soft Distemper, is more commonly used for coating of elaborate decorative plaster-work or ceilings. Its chief variant was the animal gum made from bones, horns or tender skins (rabbit skin glue). It has a very limited shelf-life, becoming rancid in a short time, and for this reason it has to be prepared and applied immediately. It is applied by brush and can be removed with a wet sponge when in need of re-coating.


Modern age distempers are available in wet form. A large number of water-insoluble film forming substances can be dispersed in water, as suspensions or emulsions. The film forming particles or droplets coalesce with or without temperature change, on evaporation of water.


The binders used, are water soluble substances, such as: Proteins (casein, glue, soya), Soluble starches, Cellulose derivatives (methyl cellulose, sodium carboxy methyl cellulose), Alginate (sodium, potassium, ammonium), Acrylates (sodium, potassium, ammonium), Polyvinyl alcohols, Sodium silicate, Guar gum, gum Arabic, Proprietary oils and Alkyd-resins.


19th Century Mongolian distemper with highlights of gold, depicting Shakyamuni flanked by Chenrezig and Manjushri