Post 343 – by Gautam Shah




For a user, occupation of a space triggers a set of behaviour. For occupation the user has to find within the space, most appropriate location, orientation, body posture, facilities, amenities, and environment. One of the most obvious place, for all these aspects, is the core zone of the space. The core zone may not coincide with the geometric centrer or the focal point architectural form.

Space and its occupation

Where no focal identity for occupation exists, the user establishes a new one. This is done by:

  • Positioning own-self at some important location (Cris-cross of many spatial lines),
  • Orienting to some feature of the space (like an entrance door, window),
  • Being closer to something (wall, column, furniture),
  • Associating with other occupants (through ‘social distancing’),
  • Being part of favourable environmental segment.



There are other operative factors that matter in occupation of a space, such as:

    • Range of cognition (capacity to perceive),
    • Physical proximity (level of social interaction),
    • Scale of relationship (age, sex, social status)
    • Possibilities of communication.

Space and Users

The user also needs to have some control over the space, such as:

  1. Opportunity to change the location and position (including the posture) within the space,
  2. Choice to interact or not with others; adjust the spatial quality at micro level (scale and schedule wise) and thereby the environmental conditions,
  3. Be noticed or notice others,
  4. Form sub-core zones,
  5. Shift to peripheral zones and be able to conduct exclusive tasks,
  6. Way to leave the space either in full knowledge of others or without being noticed.

A user, unless is an owner of the domain, will not be allowed to change the architectonic character of the space, import, shift or relocate amenities and facilities, alter the quality of environment that perhaps is not acceptable to others.


In very large spaces adjacent walls, hedges, mid columns, flower pots, water fountains, lamp posts, flooring, ceiling, and such other patterns and objects provide points of anchorage for space occupation. Spatial configurations like a stage, podiums, projection screens, speakers, singers, vivid objects, also hold interest by providing involvement.

In parties, hosts make a conscious effort to break intimate formations by removing or adding key or active persons, or repositioning and rescheduling the activities. In clubs and places of entertainment the environment (lighting, furniture, equipment) and programmes are reset to shift the focus off certain space segments. Group gatherings are designed to occupy different space segments (hall, terrace, lounge, library, garden lawn, etc.), variegated environmental conditions (bright vs diffused illumination, change of music, etc.) and diversions (toast by the host, magic shows, musical renderings, dancing, etc.).

Space for occupation

Space for occupation



Post 342 –by Gautam Shah


OLYMPUS DIGITAL CAMERA640px-Masrur_rockcut_temple

Design effort that conceives a complete and self-contained system to begin with is called a Holistic Approach. It entails germination of an intuition or idea into a complete system. Such creations are very personal, akin to a work of art. These are bizarre, and often nonfunctional. Holistic beginnings, however, are detailed further where each subsection is real and workable. Holistic ideations, without detailing remain one time achievements. Holistic approach is useful in areas where sufficient information is unavailable, or there is a distinct disinclination to search for the detail. Holistic approach is inadvertently followed when inspiration rather than logic causes a design. A holistic conception and its execution, if separated in time, some recall is required, forcing documentation of the design. With documentation the holistic creation may not remain as wholesome.

Gizah Pyramids -Holistic design

Cambridge Dictionary > The belief that each thing is a whole that is more important than the parts that make it up.

Oxford Dictionary > The theory that parts of a whole are in intimate interconnection, such that they cannot exist independently of the whole, or cannot be understood without reference to the whole, which is thus regarded as greater than the sum of its parts. Holism is often applied to mental states, language, and ecology.
The opposite of atomism.

Holistic Art by M F Hussein India

Holism (from holos, a Greek word meaning all, entire, total) is the idea that all the properties of a given system (biological, chemical, social, economic, mental, linguistic, etc.) have holistic nature. The holistic nature of a thing or concept, is beyond the sum effect of all the parts and components that are individually present. Instead, the system as a whole governs how the sub-units behave. Holism is also equated with Totalism.



Parmenides, a Greek philosopher (late 6th or early 5th C. BC), of pre-Socratic era stated that ‘All is one, nor is it divisible, wherefore it is wholly continuous. It is complete on every side like the mass of a rounded sphere’. The concept holism has been part of philosophical discourses everywhere. Holism rests on singularity of the ultimate. Indian philosophy has accepted it, but with its duality (Maya or the unreal) in all things.

ream Holism in art


Holism as an idea or philosophical concept is opposite to atomism. The atomism perceives that a whole can be dissected into its parts. The atomist divide things up in order to know them better, whereas the holism believer looks at things or systems in totality. The atomism considers everything including time to be infinitely divisible. Reductionism is sometimes seen as the opposite of holism. In science reductionism is seen as a complex system that can be explained by reduction to its fundamental parts.



At operative level a design conception can be a holistic approach. The design however, consists of many different technologies, each of which requires exclusive input. The exclusive input in the form of latest learning does not reside with the designers, but with the vendors, installers or manufacturers. These agencies can offer their exclusive input while operating in their own domain. The design as a result becomes a creation based at many locations, manifesting in different time segments and by as many agencies. The design once conceived, must go through the process of “Reductionism” or Component approach.

Bertini fresco of Galileo Galilei and Doge of Venice Search for Whole through Parts


POLYMERS -basics

POLYMERS -basics

Post 341 ⇒   by Gautam Shah 


Polymers that we use in our day-to-day life are of Four types

  1. Plastics, which are relatively stiff at room temperature,
  2. Rubbers or elastomers, which are flexible and retract quickly after stretching,
  3. Fibers, which are strong filamentary materials,
  4. Coatings, have resins with qualities that are somewhere between a plastic and an elastomer.

Panton Chair

Polyester Threads

Elastomer Shoes


Commercially available plastic raw materials can be categorized as:




Often some material combinations provide characteristics across these categories, giving very different properties and hence applications.

Packaging nuts from Thermoplastic starch

Properties of a polymer are altered substantially by inclusion of various substances. These are solids, rubbers, liquids and gases. These additive substances serve following functions.

1 Chain addition or curtailment

2 Fillers

3 Plasticizing and softening

4 Lubricants and flow promoters

5 Anti aging compounds

6 Flame retarding

7 Colourant

8 Blowing agents

9 Cross linking agents

10 Control of Ultra violet effects

Animal Protein Glue

Synthesized polymers arrived on the scene just before and after the world war II. Natural polymers, however, have been with us in plants, human and other beings body. The human body contains many natural polymers, such as proteins and nucleic acids. Cellulose is the structural component of plants.

Jelly -Alginate Polymer

Human body has nearly 100,000 different types of proteins, and all derived from only twenty amino acids. Starch is a carbohydrate found in cereal grains and potatoes, is a polymer made up glucose monomers. Glycogen, is a polymer, stored in the liver and skeletal muscle tissues, as an energy reserve in animals, similar to the starch in plants. Cellulose is most common organic polymer element. Cotton is one of the purest form of cellulose. Chitin, a natural polymer called polysaccharide is similar to cellulose. It is present in the cell walls of fungi. The nucleic acids as nucleotides form DNA and RNA. Natural rubber and Gutta-percha are plant exudate polymers.

Natural Latex Tapping

Natural polymers, derived from plant or animal sources, are of great interest in the bio-materials fields, such as tissue-engineering, bio-med transplants, medicines, eco-friendly products. Natural polymers have relevance as scaffolds on which to grow cells to replace damaged ones.

Objects made of natural polymer Chitosan

Three materials of natural origin, widely used, polymers are chitosan, collagen and alginate. The principal source of chitosan is shellfish waste and cell walls of fungi. Commercial uses include the making of edible plastic food wraps and cleaning up of industrial waste-water. Collagen is used for medical purposes and to produce gums. Alginate is refined from brown seaweeds. In extracted form it absorbs water 200-300 times its own weight. It is used as thickening agent in foods such as ice-cream and as an emulsifying agent.

Teeth impression in Alginate mould

Naturally available other polymers are: Shellac was used for sealing, lacquer coatings and as foundry casting binder, Casein derived from milk protein is used in distemper colour preparation, Bitumen were used for water proof coating and as a preservative.

Lac sealing wax

Synthetic polymers were initially conceived as replacement of natural polymers or polymer like materials. Gutta-percha was used for insulating electric cables, replaced by polyethylene and vinyls. Cellulose nitrate was conceived to replace ivory and shellac. Bakelite or Phenol formaldehyde, was used to replace wood.

Sutures made from polyglycolic acid are absorbable and will be degraded by the body over time.

Natural polymers are biodegradable. These materials are favoured for medical use, as they allow cell attachment and growth (as scaffolding) and are non-ionic and non-inflammatory. Many of these materials are highly porous and lightweight.



Post 340 ⇒   by Gautam Shah 


An enamel is the hardest substance in the human body, in the form a cover on the teeth, consisting chiefly of calcium salts. Substances similar in hardness were produced through a glass-ceramic route. The word enamel derives from smelting or smelzan (German) or smalto (Italian), email (French and German), and enamel (English). Smelting as a process is very old, used for extracting metal by heat processing the mineral ore. Enamelling uses similar processes of material conversion.

10th C gold and enamel Byzantine icon of St Michael, St Mark Basilica

Enamel, is defined as a vitreous, glass like coating fused on to a metallic base. Through the history, enamels have been applied on gold, silver, copper, bronze and iron surfaces. The term is also used for many other applications that provide tough and a glossy surface such as the fusing of glass over glass, fired ceramics, and paints.

Enamel is formed from substance known as flux, frit or fondant. For enamelling the paste consisting of mixture of silica (from quartz or sand), soda or potash, and lead are deposited on to metal objects such as jewellery, small metal boxes, utensils, ceramics or glass, and fused by heat. The resultant surface is chemically identical to glass or highly vitrified ceramic, almost clear, with a slightly bluish or greenish tinge. The surface can be made opaque and coloured by the addition of other metallic oxides. When the temperature to fuse the materials is very high, the enamel formed is hard. Soft enamels are easy to produce and are more conventional.

Enamelled Signage

The brilliance of an enamel depends on the perfect combination of its ingredients and temperature. The colour is achieved by a change in the proportion of the ingredients of the flux than by an increase in quantity of the oxide.

Enamel Watch dial

The earliest known enamelled objects were made during the Mycenaean period during 13th C BC. Since then through history jewellery had applique colours of enamels. Arms’ handles and armour cases, mirrors, furniture handles, decorative dishes and bowls were embellished with enamel. Ceilings’ and doors’ metal panels were enamelled. Religious ceremony items such as cups, bowls, caskets, crosiers, were enamelled. Dials of table, pocket and wall clocks were adorned with enamelled numbers. In India jewellery and small boxes were enamelled, known as Minakari work.


White Enamel ware Image from

With the onset of 18th C., Cast iron vessels for home and other uses began to be used. These enamelware were with little colour or patterns. The vessels with white enamel coating were known as white-ware. Hospital-ware such as gandy, urine pot, kidney tray, instruments’ tray, camping-ware and army-ware like tumbler, bowls, dishes, and public signages were made with enamelling. The white vitreous enamel linings, was also called porcelain. It was used for lining cooking stoves tops, oven doors, sinks and washbasin.

Stove -White Enamel goods

There are two main methods of applying enamel to metal. Champlevé, in which hollows made in the metal surface are filled with enamel, and Cloisonné, in which strips of metal are applied to the metal surface, forming cells, which are then filled with enamel. With these two basic methods Six types of enamelling techniques have developed: These are Champlevé, Cloisonné, Basse-taille, Plique-à-jour, Encrusted, and Painted enamel.

Champlevé type 12th C armlet, so showing chased recesses for the enamel

1 Champlevé (French= raised field) enamels are done by scratching or etching a metal surface, usually copper, leaving hollows or troughs with raised lines between them. The hollows are filled with pulverized enamel and then fired. The hard-finished enamel is subsequently filed down until the glossy surface and the metal surface can be polished simultaneously, with crocus powder and jeweller’s rouge.

Cloisonné enamel plaque, Byzantine Empire, ca. 1100

2 Cloisonné (French= partitioned) processes, uses very small partitions, or cloisons, consisting of thin metal strips, built up on the surface of the metal. They may present a pattern and are fixed to the surface by the enamel. The Cloisonné technique is usually applied to silver, although gold or copper may also be used as bases. Cloisonné techniques originated in 4000 BC.

Basse-Taille type enamel Royal Gold Cup, 236 high x 178 across 14 C

3 Basse-Taille (French= low cutting) process is a kind of champlevé but is applied to silver or gold. The metal is engraved or hammered to various depths according to the design. The depressions are then filled with translucent enamel, through which the design beneath it can be seen.

Silver-gilt set with plique á jour enamel plaques, and gold cell-work

4 Plique-à-jour (French=open braids) enamelling resembles cloisonne, but differs from it in that the partitions are soldered to each other rather than to the metal base, which is removed after firing. The remaining shell of translucent enamel gives the effect of stained glass. Plique-à-jour enamel is exceptionally fragile because it has no metal base.

Gold, encrusted (en ronde bosse) enamelling 1517

5 Encrusted Enamel or enamel en ronde bosse, involves the spreading of an opaque enamel paste over the slightly roughened surfaces of objects such as small figures.

Pocket Watch, 1750-1800, painted enamel portrait

6 Painted Enamels resemble small oil paintings. A metal plaque is covered with a layer of white enamel and fired. The design in coloured enamels, is then applied to the white ground, by painting, spraying, screen printing, or block printing, separate firing may be required for each colour because each may fuse at a different temperature. Painted enamelled miniature portraits were popular in Renaissance period.



Post 339 – by Gautam Shah




Elevators are intermittent transfer systems that moves goods and people in a direction perpendicular to the gravity. This is unlike the inclined stairs and escalators or almost parallel to the gravity systems like corridors, passages, roads, lanes and automated walkways. Elevator systems are modulated transfer systems in contrast to the uninterrupted transfer entities, and so have limited capacity of conveyance.

1 Well with bucket Ichijodani

The efficiency of a transfer system is determined by the fact whether the system is parallel, inclined or perpendicular to the gravity. The additional effort required to work against or towards the gravity, respectively retard or add to the efficiency.

2 Coal Miners- Everyday Life in a Midlands Colliery, England, UK, 19442 Miners Caged Bucket LiftThe intensity of transfer depends on whether the system operates continuously or intermittently. Continuous systems such as the escalators, automated walkways, conveyor belts, are governed by the speed of movement, while the intermittent systems such as the elevators, buses, railways are affected by the size capacity of the module, speed and frequency of service. Both systems, however have some traffic capacity limitations.

2 Old Selfridges Lift Wikipedia Image by Tony Hisgett from Birmingham, UK3 Elevator lobbyAn elevator system is capable of elevating or raising a load to a height. Lifting devices such as rope and a smooth axle were used to draw water from wells and lift building stones. The smooth axle was replaced by a wheel or pulley. The first documented proof of a lifting device is by Roman architect Vitruvius, who reports Archimedes (Greece 236 BC) building it. Ancient and medieval elevators used drive systems based on hoists or winders. These were inefficient methods. The use of a screw drive and multiple pulley systems, were the most important steps in lifting technology.

4 Scissor Lift Wikipedia Image by SmialElevators are manual, mechanical or power driven systems. Manual elevators are now used for small weights and low elevations. Manual elevators are free-fall and pulled or assisted-rise, or controlled fall-rise types. Some are partial combinations of both types, i.e. the rise may be free due to the counter weights, but fall may be controlled (such as dumb waitors from top floor kitchen facilities), or the system may work other way round. Fall is controlled by provision of a counter dead weight or parallel module. Mechanical grips that control the accelerations of speed during fall are also used. Fall is required to be controlled to avoid damage to the bucket or car module of the elevator, its resting place, noise due to impact, vibration during uncontrolled descent, spillage of liquid and breakage to fragile items like crockery etc. Fall is also required to be controlled so that stops match the required datum. Control of the rise is not very problematic in manual elevators, because there is no self acceleration during ascent. Rise of a weight (dead or a purposive load) to be elevated, is accurately controlled by the amount of energy expended. However some control mechanism to maintain the rise once gained, is required. Such dumb waitors are used between kitchen and serving areas, godowns and delivery areas, documents and spare parts transfer in commerce and industries.

4 Dumbwaiter geograph-4379493-by-Bill-Nicholls

Bucket-lifts were common for water wheels in India, Persia and many other countries. Bucket-lifts were also used to lift ore and coal from deep mines, and transfer miners. An air lift system works on a suction mechanism to transfer materials.

The classifications here are oversimplified discussions for the non technical people.

Mechanical Elevators use some form of chain pulley system or other devices to reduce the energy required. Such elevators are capable of lifting larger loads than dumb waitors. In some cases the elevators are designed as quasi mechanical systems, where rise is through a mechanical or power driven system, but the fall is natural but controlled. Such systems are used where, loads heavier than the manual capacity are to be lifted, power supply is erratic or not available, lifting requirements are occasional.

6 Mechanical Lift geograph-734490-by-Stephen-Sweeney

Power driven elevators are generally motorized, where an electric motor creates a hydraulic pressure or winds a traction rope to elevate a weight. These elevators work on DC current to regulate the start, speed and stop.

2 miners mechanical hoist

Hydraulic Elevators are not extensively used now, however, are ideal for low rise building where design limitations preclude overhead supports and machine rooms or load-bearing walls around lift well. The machine room can be located nearly anywhere, and let one maintain a flat roof line and save money on construction. Geared traction elevators are ideal for low-to medium-rise buildings, where high speeds are not essential, though speeds up to 400 ft/min. can be planned. Gear-less traction elevators are recommended for high-rise applications requiring the ultimate in service-speeds of 500ft/min and up.

Eiffel Tower Lift Cars

Passenger elevators are wide and shallow in depth, with centre-opening double doors or single side doors. Service-elevators, like for hospitals, are narrow and deep. Combination passenger and service elevators should be almost square. Freight elevators’ size and shape are determined by the dimensions of goods to be carried and by the loading / unloading methods used, but nominally allow carriage of 1200×2400 sheet materials.


While providing elevator system in a building, two basic norms are considered. The frequency and quantity of service required, and the quality of services desired. The quantity of services is determined by the passenger handling capacity during peak periods, while the quality of service is measured in terms of time required (waiting time) to avail a lift. The quality of elevator service is determined by the building planning, intensity of peak hour requirements, extent and duration of traffic, frequency and urgency of service required, type and control mechanisms, type of landing doors, etc.

Pan Pacific Singapore Open or Bubble elevators Wikipedia Image by SanchomOperation of lifts: Modern lifts have an electronically intelligent control system that actuates starting, stopping, door opening and closing, direction of motion, acceleration, speed and retardation, emergency smooth fall of the lift car. A variety of motors are used to power the lifts. The simplest is single speed resistant AC motors, the reduction gear is attached to the pulley, braking is semi mechanical, or through an additional motor, generally a DC motor. In a little more complex setup reduction gears are attached to the motor and a secondary winding is provided to stop the motor. More complex and accurate system consists of a DC motor. With DC motor input voltage can vary the output speeds, step-less gear system is often integral part of the motor. Such systems provide very high speeds, accurate stopping, less jerks and smooth operation.

11 Platform_window_cleaner

12 Bus Elevator for wheel chairs Image credits Aktron Wikimedia Commons.Elevators are prerequisite requirements for buildings taller than 3 floors. Elevators are often a legal requirement in public buildings because of wheelchair access laws.




Post 338 – by Gautam Shah


There is a common belief that Interior Design as a skill has originated from Architecture. This view gained strength from the fact that Architecture itself, as a unique skill branch, separated from the Building Engineering. Architecture, though, has facilitated other skills like Urban Design, Town Planning, Landscape Design. Interior Design as distinctive skill-based business has emerged due to distinctly different circumstances.

Firm of Herter Brothers, New York, (1864–1906), by Gustave and Christian Herter begun as an upholstery warehouse, became one of the first firms of furniture makers and interior decorators in the US after Civil War.

A building once constructed is initially readied for occupation by the original designer. However, buildings last for ages, and during the lifespan, must be altered and updated several times. Original building engineers or architects are unavailable or unwilling for such assignments. They do not have the income incentive for such ‘frivolity’. During early middle ages, or perhaps even earlier, low skilled ‘art -painters’ or artists’ assistants were hired to paint and decorate old buildings. The building decorators, worked along with their associate crafts-persons, like Iron smiths, Guilders, Glass blowers, Weavers, Embroiders, Rug and Carpet makers, Sculptors, Mural makers, etc. They would together undertake repairs, make furniture and update furnishings. These diverse services were coordinated by the Building Decorator. The services of decoration gradually emerged as a distinct business from Architecture or Building Engineering. The building decorator was neither a variant, nor subservient to the architect.


The decorators worked as a facilitator, scheduling and coordinating the activities, while supervising the quality of various vendors. The services of the decorator were more frequently required for resetting the interior spaces, than for exterior updating. The interior decorator gradually began to offer design alternatives and devised specific design solutions. Interior decoration became a well-documented strategy, serving two basic purposes.

  1. It showed the user or client, in advance, the solution, in a representative form -a surrogate.
  2. It helped creation of a functional system by coordinating skills, materials and objects, sourced from different agencies.

Once the second objective was achieved without being continuously present on the site, it was possible for the Interior in charge person to devote more time and attention to the first objective.

The Interior decorator began to play a very active role of a professional interior designer, rather than being simply a site bound contractor. The Interior designer now operated from a Design Studio, usually located in an urban area. The studio was used for creating drawings, sketches, other presentations, models, pilots, prototypes, dummies, and cartoons (replicas of artwork in full size). It contained material-samples’ catalogs. The studio was a fixed location where clients, suppliers and crafts people were able to meet the Interior designer.


The physical distancing of a studio from the site also separated the Design and Execution aspects of the interior practice. In the combined practice of Design + Execution, the need for a documented scheme was not very acute, as decisions immediately turned into actions. However, in pure (only) design practice, all decisions had to be not only communicated, but very often formally transmitted as an assignment to the site-based agency.

Schematic documentation of design of Interior work has been very difficult compared to Architecture or Building Engineering jobs. Amateur and untrained interior designers lack the capacity to document their design intentions, so prefer to work on the site, providing oral instructions to contractors or their workers. Many Interior Designers, even to day, where practicable would like to execute their work by themselves. The tradition of combining design + execution persists for many reasons:


1.      Interior components require complex details and sensual materials. These are difficult to present through formal design documentation, and can be implemented only through personal involvement.

2.      Interior designing involves improvisation. The coordinated effect can be achieved, only when components or systems are substantially produced by the designers themselves.

3.      Interior design involves use of many crafts. Human resources and craftsmanship, unless fostered at home may not be available on required occasion.

Kimbel and Cabus was a Victorian-era furniture and decorative arts firm based in New York City.



Post 337 –  by Gautam Shah 



The art of Oil painting developed in Europe in the late Middle Ages. It was widely accepted as a better art medium, as it was easier to work with and allowed a greater variety of effects in comparison to the (than available) other media, like encaustic paint, tempera, water colour, fresco, etc. Oil painting dried relatively slowly with little change in colour. Tones are therefore easy to match, blend, or grade, and corrections easy to make. With this medium the painter was not limited to linear brush strokes, but could apply paint in glazes, washes, blobs, trickles, spray, or impasto (textured effect). The painter was no longer restricted to a prearranged design, as the slow drying system allowed change, improvisation and over work. Rich effects were possible with colours, tonal contrasts, and chiaroscuro (shading). Jan Van Eyck, a Flemish painter in early 15th C. explored the oil paint as medium to work over the tempera style of paintings. The Venetians took it the further with oil painting on canvas.

Women of Algiers Oil painting on Canvas 18 C

Alchemists shop with Concoctions

Early oil paints were made by modifying the drying oils like walnut or linseed with natural gums such as amber, copal, pine-rosin, etc. The oils were cooked, or exposed to air and sunlight. But later, cooking was conducted in closed kettles under pressure and in absence of oxygen. These ‘stand oils’ were modified with natural gums, resulting in viscous substance. The viscous substances were reduced (diluted) with turpentine.

Johannes Vermeer, The Milkmaid (1658–1660) Oil Paint

Modified drying oil mediums were found to be good for wood surfaces, unlike the tempera colours. The grains and texture of wood surfaces helped in binding the medium. It was also realized that the medium should have a better body (high viscosity compared to pure oil materials) and drying properties, otherwise would run (drip down).

Safflower oil as paint medium

art_supplies_artist_art_supplies_creative_color_paint_pastels-816166.jpg!dLéon_Bakst_-_Bathers_on_the_Lido._VeniceOILS AND OLEO-RESINOUS BINDERS

OILS: Vegetable oils and animal fats are the oldest binders known to man, some of which are still in use today. The suitability of an oil as a film forming substance depends on the highly unsaturated fatty acids. To make raw oils usable, three treatments are carried out 1. alkali refining to reduce the acidity and improve the colour, 2. kettle bodying -heating oils for a prolonged period at high temperatures to increase the viscosity and polymerizes it, 3. blowing air or oxygen through oil at elevated temperature to increase its oxidation.


Types of Oils: Drying oils (Linseed oil, Tung oil -china wood oil, Dehydrated castor oil), Semi drying oils (Safflower oil, sunflower oil), and Non drying oils (olive, castor, cotton seed, coconut oil). For coatings drying oils and some semi drying oils are commonly used.

Flax plant to Linseed oil

Oils have been treated with many types of processes and substances. This included metallic salts. There were many problems with oil modified film forming substances. There was colour darkening of coating on ageing. It was not possible to create long lasting lighter colour shades. Over oxidation made the film very weak. Presence of natural gums made the film tacky in moist weather. The process of polymerization was not clearly understood.

resin-2290750_640OLEO-RESINOUS BINDERS: These substances are often combined with oils, bodied oils or their resins. Rosin is a low-cost resin derived from sap of mainly Pine trees (abietic acid). It is neutralized with lime (to form calcium Rosinate), glycerin (ester gum) or penta-erythritol (penta). These substances are now used in low cost paints and varnishes, or as cost effecting additives. Coumaro-indene (cumar) resins are derived from coal tar naphtha, and are used in leafing aluminum paints and other low cost systems. Phenolic resins are produced by reacting synthetic phenolics or phenolic compounds (cashew nut shell liquid) with formaldehyde.

Resins oozing out of a fresh cut in a tree

Gum Arabica

The technology of oil coating, in spite of its many drawbacks was very popular. It first came into being as the art media, but soon began to be used extensively in upgrading the interiors of mansions and palaces. It was the beginning of oil based architectural coating system.

Oil Paint work on Gopuram (Gate structure) of a Temple Chennai India

With the onset of industrial revolution the use of iron and ferrous alloys became extensive. Not only coating materials in large quantities, but for specific surfaces were now required. Rusting was a major problem with metal surfaces. Many protective coating systems were developed.

Semporna Sabah Multicoloured longhouse

During world war II, availability of natural oils such as linseed, castor, etc., which were of Asiatic and transatlantic origin, was affected. At the same time several petroleum-based products and derivatives began to be produced. These prompted research on non oil resins. Such chemically polymerized resins had faster drying time, better toughness, finer gloss and superior colour fastness, then heat bodied mediums. Polymeric resins both, thermo-plastic and thermo-setting varieties were produced.


Alkyd resins first came into use in the 1920s. These first alkyd resins (first polymerized polyester resins) were merely the reaction products of phthalic anhydride and glycerine. These products were too brittle to make a satisfactory film. The use of oils or unsaturated fatty acids in combination with the brittle alkyds resulted in the air-drying coatings which revolutionized the coating industry.

Architectural coatings

Alkyd resins form the basis of most of the commercially available glossy paints, flat paints and primers. These are produced by reacting drying and semi drying oils with a phthalic anhydride (acid), glycerin and penta-erythritol. Resins which have smaller proportion of oil -called short oil alkyds, or have oils of semi drying type, are used in baking finishes or as plasticizers. While long oil alkyds are used for air drying finishes or GP Enamels. Typically a long oil alkyd will take longer to dry out but may have higher strength, and a short oil alkyd may require baking to aid the drying.

Synthetic resin manufacturing through a complex plant

A variety of alkyds are produced by modifying them with other polymeric compounds. These modifiers are like: Rosinated alkyds, phenolated alkyds, styrenated alkyds, silicone modified alkyds, epoxy modified alkyds, acrylic modified alkyds, vinyl-toluene modified alkyds, and urethane alkyds.