Post 190 –by Gautam Shah




Objects are seen when illuminated. Light illuminates objects, but in the process affects it in several ways. Some light is absorbed within it which is mainly responsible for perception of colour. If the object is transparent to translucent, than part of the light gets transmitted though it. The transmitted light (through the object) may get re-reflected through the object. In the process the re-reflected light gets scattered. Light also gets specularly reflected from it the surface of the object provided it has reflective properties.



Nearly reflective surface -Glossy coating on wood

Specular reflection: The substantial quantum of light is reflected from the surface, in equal and opposite direction, to the angle of incident light.

Diffuse reflection: The light that gets scattered in many directions.

Vietnam Veterans Memorial, National Mall

lathe turned pillars chennakeshava_temple_in_belur

Gloss is one of the most important of parameters that describe the visual appearance of an object. It is an optical property of a surface to reflect light in a specular (mirror-like) direction. A specular reflection can be said to be a reflection in very small range of direction. This is distinctively different from diffuse reflection, where the incoming light is reflected in a broad range of directions. Factors that determine the gloss are the refractive index of the material, the angle of incident light and the surface topography.


early american room

Distinctive examples of specular and diffuse reflections are glossy and matte paints. Matte paints have almost exclusively diffuse reflection, while glossy paints have both specular and diffuse reflections’. A surface of a non-absorbing material such as plaster, are nearly perfect diffuser, whereas polished metallic objects, glass, and some polymers are specularly reflective.


chicago_bean shiny_mirroring_mirrored-1001730

Texture of a surface is a key determinant of level of specular reflection. Objects with a smooth surface, i.e. highly polished or containing coatings with finely dispersed pigments, appear shiny to the eye due to a large amount of light being reflected in a specular direction. Rough surfaces have irregular defects or undulations which scatter the light in other directions, and so appear dull. Dull surfaces do not reflect the image (like a mirror), so the reflections seem blurred and distorted.



In case of transparent and translucent materials, not only there is surface level specular reflection but the back face coatings-treatments and closely placed materials (substrate materials) also reflect specularly. The reflecting material of mirrors is the highly polished surface of glass, and its capacity to reflect light from the back side coating of lead, aluminium or silver.

1 matt.jpg

Gloss is often considered a subjective term (though scientific tests exist) for representing specular reflection of a surface. Commercially, in the surface finish world, gloss is recognized as Flat or matte, Egg shell, Semi-gloss, Full gloss. A Flat surface is considered free from sheen even when viewed at an oblique angle whereas at the other extreme Full gloss is a mirror like face at all angles of view. Satin (silk) finish is somewhere between Egg shell and semi gloss finish.

A rough guide for level of gloss of a surface is: Flat (0 to 10 % reflective), Low Sheen (10 to 25% reflective), whereas Glossy (70–90% reflective).


Dull-matt surface

Dull- matt surface Unglazed Ceramic

  • The non-reflecting surface of a flat-matt finish helps to hide or de-emphasize the imperfections of the surface to be painted. Semi-gloss finish and high-gloss finishes highlight such imperfections. Flat-matt surfaces do not reflect light at any angle so are very useful as a coating-finishing over very extensive surfaces such as corridors, lobbies, halls, ceilings, and exterior faces, etc. Flat-matt finishes over the floors, also offer an assurance of their being no slippery surface. Flat-matt surfaces show off true colours at all angles, so are visually more recognizable. Flat-matt surfaces may look patchy if the substrate or the application techniques are improper. Automobile interior trims are intentionally designed to be of matt finish so as to minimize the irritating reflection while driving.

Reflective-Glossy Roof

Walt Disney Concert Hall LA CA

Walt Disney Concert Hall LA CA

  •  Semi-gloss and full gloss finishes offer better wearing, cleaning and humidity resistance than flat paints. Flat paints may show polishing or burnishing marks when rubbed for cleaning. Semi gloss surfaces are slightly deceptive and may not show true colour or depth perception.
Brushed Matt metal finish

Brushed Matt metal finish

  •  High gloss surfaces get easily tarnished by oil, grease or waxy streaks. High gloss surfaces are first to show off substrate impurities and malfunctioning of plasticizing agents or entrapped moisture, etc. High gloss surfaces show of minute scratches or dents etc. in terms of defective specular reflection. High gloss surfaces are very deceptive in colour recognition.




Post 189 ⇒   by Gautam Shah 

Dimensional coordination

Ancient measure systems were based on the human limb sizes and body’s capacities. These were function-related measures such as: foot size and walking, thumb and width, fingers and numbers, palm and holding capacity, head load or horse power and carrying capacity, etc.

In a series of measure units, the sub units, though body related, were nearly independent. The interrelationships between sub units were simple but enforced. Various measures’ series were mutually incomparable and to an extent incompatible.

Across the world there were innumerable measure systems, but the Foot-Pound system became dominant due to extensive colonization by the British Empire.

The Metric System (created in France post Revolution period) was an abstract system with a Mathematical Order. It had the advantage of Logical Fractions. All measure units were divisible to 10X. But (early) Metric system had several sub units, many of which had no effective use. For some people the rationale of Metric system was too contrived as its scale did not relate to human body and its parts-whole-parts relationship.

In thePost Industrial Revolution‘ period, trade and industry all over the world recognized the need for a Universal Dimensioning Discipline. At that time better coordination was also required for conversion and transmission from old measurement systems to the new SI system of measurements. First worldwide understanding emerged in the adoption of SI as the Universal Measure System.


40 – Modulation with Body based Measure systems


41 – Foot-Pound (British) and Metric systems of measurements


42 – Need for a Coordinated Measure system


43 – Universal Dimensioning Discipline


44 – SI system of Measures


45 – ISO Modular Preferences -1


46 – ISO modular preferences -2


47 – Application of ISO Modular preferences


48 – Implications of ISO Modular coordination of Dimensions


49 – Implications of ISO Modular coordination of Dimensions -2


50 – Implications of ISO Modular Coordination of Dimensions -3

  • If you are following my Blogs here, and if interested in this topic you may seek entire Power Point Slide show by sending your e mail id.



Post 188 –by Gautam Shah


CCD Sensor Chip

New technologies for doors arrive more frequently due to developments in materials technology, and also occasionally due to design innovations. Improvised doors are offered by building components’ manufacturers, and sometimes devised by creative designers. But ideas for radically different types of doors have been adopted from literature like scientific fiction, children’s stories of adventures, media such as scientific movies, television serials, and from video games. New doors have been modelled on various gadgets and industrial equipment. Unusual opening systems have come from submarines, space capsules, cameras, chemical reaction vessels, dams, dykes, deep sea drilling units etc. Such opening systems may not be recognized as a door, but rather function like a valve or controller of opening.

Gates controllers, mechanical moving components, Carcamo of Dolores. Bosque de Chapultepec, Second Section, Mexico City. Wikipedia Image by ProtoplasmaKid

Openings serve some basic functions, individually and collectively. The individual functions remain add-on technologies, becoming bulky and spatially sequential, whereas collective systems are integrated and so efficient. Individual systems can be adopted as per the needs in both, time and space, but integrated systems are mass produced and one must accept whatever parameters the manufacturer offers.

Access control security gates provide layers of protection Wikipedia Image by Nuclear Regulatory Commission

Opening systems, in traditional buildings serve many purposes like vision, ingress, illumination, ventilation, degrees of privacy, security, etc. These required an assemblage of multiple solutions. Such solutions had many mechanically moving components. Each movement system needed its own operative energy, controls and often lubrication. Electronic or digital systems are local, the controls could be wired or through electronic waves. These are too small, without moving components  and cheap enough to be replaced easily. Digital components are rationally designed and so have inherent ports for replacements.


Hangar One at Moffett Field 1963 USA with segmental folding doors


Isolation areas in research laboratories and nano technology plants require hermetically sealed zones need doors with a positive seal (completely leak-proof). Very large and light weight structures, such as domes and roofs require openings for access to external face. Such circular flexible doors of membrane or skin thin materials diverge to edges for closing, but bulge or sink to a concave or convex form due to suction or pressure. Heart valves are implants that beat, but function like a door. Air curtain fans and showers create a wall of cascading air and water, but a breach-able door opening. Similarly sonar zones, in industrial plants remove particulate matter from the things that move in or out are also a door system. Offshore or deep sea marine structures such as oil-gas drilling platform and recovery or collection centres, coastal protection barriers such as dykes have doors for water. The water gates were once devised as very large geometric or space structures but are now built as membrane or shell structures.


PVC strip door for warehouses eliminates the bother of closing-opening

Industrial doors are very large and intensively used openings. Normal sliding, folding or swinging shutters take a lot of time to close or open and with every such operation the interior environment gets corrupted. Air curtains are noisy and cold. Flap curtains of non tearing polymer or composite sheets have proved a better option. Ion charged openings and sonar barriers are not very satisfactory in many applications. Some radical solution is required.



A pound lock on the Keitele-Päijänne Canal at Äänekoski in Central Finland

A pound lock on the Keitele-Päijänne Canal at Äänekoski in Central Finland


A door is perceived to be an opening in a barrier, an open-able component of the barrier system. However, if whole of a barrier were to disappear, collapse (physically shrink) or become non-functional for a while, then it can serve the function of an opening. A barrier will have to collapse to its edge or perimeter, away from its centre, almost like the folding leaves of a camera shutter. Here the leaves could be of gaseous or liquid substance, or a field of energy. Games, science fiction and movies explore such radical concepts.



A door has traditionally served the purpose of entry and exit to and from a space and one world to another to another (earth to heaven or hell). Egyptians painted an image of a door but new modes of transfer, transport or travel such as in movies and TV serial Star Trek. Tele-porting may entirely change the shape, size and configuration of the door in future, perhaps it will be a controller of opening rather than a door. An opening that can be cut anywhere in the barrier or membrane, a self seaming door is a sci-fiction concept emulating the biological healing.


Star Trek Teleportation -a door to another space



Post 187 –by Gautam Shah


Types of Specifications in a Design Practice

A Design Office generates a variety of Documents that contain some or the other forms of Specifications. Such Specification related documents are of following categories:

  1. Drawings, Graphical representations
  2. Literary explanations
  3. References to other Graphical Representations and Literary explanations, Legends, Indexes, Lists.


Quality of Expression in Specification Writing

Writing Specifications is the most important way of facilitating a product or service. Specifications writing is an extended activity of contracting, so here too all the contract fundamentals are strictly followed. Such as a contract has to be enforceable, and whatever is specified must be doable. Specifications cover all valid and essential requirements of the job. A major danger in writing specifications is to include unnecessary information, choosing what to exclude is as important, as choosing what to include. Specifiers (Designers) must eliminate any requirement that adds no value to the Product or Service being acquired. The Specifier (Designer) must state clear conditions in a complete language, and yet remain brief.


Defects in Specifications and Liabilities

Very few specifications are totally free from defects. As a fundamental principle of law, a specifier (Designer) is responsible for the consequences of the specifications. Designers usually put in a disclaimer (in the contract with their client) for errors found in their work. The Insurance companies that cover the designers for Professional Liability (Professional Indemnity Insurance) insist upon it.


Most of the specification writers (Designers) incorrectly presume that their text of specifications is read and interpreted by comrade technocrats only, with whom they share similar experience and mind-set. Specifications, however, are more attended by non technocrats like the administrators, lawyers, jurors and judges. A contractor or vendor interprets the specifications, as long as the interpretation is commercially reasonable (read as an earning proposition).



Accuracy and completeness of Contract Specifications

A Contract is in force the moment it is signed, or dated to be effective. Once a contract comes into force, any thing that has been left-out, or not properly defined, can be only corrected through a Negotiated Supplementary Agreement. A Contract and Specifications must not leave out any aspect, as something to be agreed or determined later on (e.g. a clause like: plastic paint of x quality, but colour shade to be approved later).

Specification Writing is a last moment compilation, and as a result it is common to see specifications of items that do not exist, or have been eliminated from the project. Specifications of only intended items and required quantities of work should be provided to the contractor. Otherwise, the bids will reflect the necessity of being prepared to handle Intended items and Quantified work.




Post 186 –by Gautam Shah



Interior of the Cube Houses, Rotterdam, Procince of South Holland, Netherlands

Buildings are tilted, often intentionally for de-constructionist attitudes or for doing something bizarre. In such buildings, though walls, roofs, etc. may change, but there are many other elements, such as floors, openings, stairs, etc. that must remain steadfast and operatable. These entities, though find a place as dysfunctional surrogates. Some impose highly moulded peripheral items to enforce a ‘change’(Gaudi) or cover-up such mandatory items with skin (Dresden cinema) that is easier to mould.

Ufa Cinema Centre Dresden Kolossos

Gaudi's Casa Batllo Barcelona Spain -Masked windows


The Cube Houses in Rotterdam, The Netherlands viewed from Blaak Subway Station Wikipedia Image by Raul Ayres

The ‘Vermont window’ often known as witch window, coffin window, lazy window, or simply a sideways window were not borne out of a modernist attitude or a desire for doing something different. It was rather a practical well-fit-in solution. It is normally a double-hung sash window or a single-sided casement window, placed in the gable-end wall of a house-roof. Its placement matches the slope-angle of the roof -usually at 45°. The window fits in gable side small space between the normal roof and its raised portion. Roofs have dormer windows for attic spaces.

A Vermont or witch window, Irasville, Vermon Piledhigheranddeeper at English Wikipedia

witch on broom

Vermont windows are called Witch windows, no one knows with surety, for why? It is not clear what preceded the window or the myth that relates it to the witch. The myth relates to a belief that a witch cannot fly with the broomsticks through a tilted opening.

coffin window or Vermont window

Vermont windows are also called Coffin windows. The position of the window at second floor level, its width and inclined position will not ever allow removal of a coffin, even if one want to avoid a very narrow staircase.

Vermont windows are found in farmhouses from the 19th C, and Vernacular architecture of central and northern parts of Vermont State of USA.

Toronto Royal Ontario Museum1



Post 185 – by Gautam Shah


DCF 1.0

Interpersonal relationships signify the social interactions between two or more people. Interpersonal relationship at one extreme could be very intimate, or physical, and at the other extreme very casual and detached with no apparent contact except recognition of others’ presence.


The interpersonal relationships flourish in space that facilitate such interactions. It needs space for recognition, perception, expression and communication. One of the prime characteristic of such a space is its size or depth. ‘Adequate depth of space’ allows control over how much one want to distance own-self from others. For some personal encounters depth of a space determines the privacy, intimacy and security. The depth aspect of a space can also be debilitative factor negating the seclusion, familiarity and protectiveness.




Interpersonal relationships have less relevance in acutely sized and defined spaces (ergonomically sized, shaped and provisioned with very specific facilities), such as: toilets, kitchens, storerooms, study nooks, booths, etc. Spaces with a greater dimensional adequacy permit better recognition and perception. Security is also operative in a crowded space or participatory public space, as such places do not permit privacy or intimacy. Spaces with satisfactory depths allow time for decision making whether one wants to allow a relationship to flourish or not. It also allows sufficient time and space to improvise the body’s gesture, posture and orientation and thereby ‘correct the impression’.


Body posture, gesture and orientation vis a vis other person, are very important factors. All three begin to switch, the moment one realizes of being perceived. And, one needs time and space for the required improvisation. Often one needs momentary seclusion to effect the transition. The seclusion could be through furniture and other architectural elements or occlusion from perception range of the other person. It could also be achieved by intentional diversion.


Groups, to an extent subsists on spatial characteristics for expression and its perception and so the interpersonal relationships. Group level interpersonal relationships could be centric (one leader-many followers) or participatory (everyone involved in the process). The perception of a group leader and others may be partial or occluded (such as the audience in darkness) or fully perceptible (such as a round table conference, press interactions, discussion-workshops). In virtual communication modes the ‘depth of space’ required is irrelevant for domains like telephony or video conferencing, chat rooms, hangouts, etc.


Waiting Architecture Tate Building Shadows People



Post 184 – by Gautam Shah



We endeavour to create Single Material Objects. Objects made of single material, whether natural or man-made, have inherent efficiencies. We try to achieve the state of a single material efficiency by integrating or by synthesizing different components.


  • A window consists of a structural frame, shutters, glazing system, mosquito-nets, curtains, weather-sheds, etc. It would be ideal if one integrated system, made up of a single material were to serve all the purposes.


  • Similarly a roof is made of the structural slab, outer side water proofing coat, insulation, and floor finishes, and under side plaster, an acoustic ceiling, etc. It would be very efficient to have one material serving all these functions.Roof – multi layer.

elements of roof

  • A partition is designed to divide a space in terms of visual privacy, safety, stability, sound proofing, fire proofing, heat insulation, provisions for apertures and services, etc. The partitions as a result consist of a structural system and various layers, each designed for specific need. The partition is further coloured and textured for use requirements. The structural elements, layers and the surface treatments can be replaced by a single material-object system. Composite panels for partitioning, is a first attempt in integrating various sub systems.


640px-Back_side_of_National_Parliament_of_Bangladesh_20A single material system capable of serving many different purposes is not easy to devise. Such an event takes years of effort. However, human ingenuity out-paces such attempts, by inventing superior but totally a different entity, for the given situation. The superiority of a newly invented entity may not be due to the unitary structure or the multi purposiveness of the material, but for its multiplex system of simpler and lesser number of elements.



An automobile, a computer or a building, is formed of as many parts, as they consist of different materials. If one can reduce the number of parts, automatically the number of materials used, will come down. If a conscious attempt is made to reduce, the number materials used, then there will be reduction in number of components.


At any cross section of time, we find a large number of materials systems either are overtly attached to other objects, or are in the process of being integrated with them. It is very desirable that an object system in such a situation, be singular in constitution or at least be effective in that manner. Designers aspire to provide a singular object system in place of a multi-component system. In designers’ world, however, there are very few situations where singular object system can satisfy all the demands in a particular time-space profile. Multi-component surface systems are reality.




Post 183 – by Gautam Shah 


ISO began its work primarily with the formation of standards for measurements, such as: specifications for writing and coordinating measures. The Standards for Measurements offered a universal approach for measurement systems. Subsequently ISO began to evolve International Standards for Products, Services, Processes, etc.

In all human endeavours, each citizen (or a being) is considered a stack holder. So one has to be conscious and conscientious of all our actions. It was accepted that for a consistent and all-inclusive care, an attitude at personal level, and a culture at organizational level is necessary. This can only be achieved if a person or the organization strives for continued excellence, and develop a synergetic system to achieve it. Many individuals and organizations have such ingrained mechanisms, but, often, these are not comparable in terms of their intentions or effectiveness.

Stack Holders

Small organizations may not have any official system as it is owner driven, running things in ‘own-way’. Large organizations, however, need set procedures, documentation and some degree of transparency. ISO management systems help achieve these objectives in a manner that is common across industries and other organizations and consistent across the world..

Evolution of ISO 9000 standards

In the last two decades ISO has concerned itself with Quality, Safety, Security, Environment, Food, Health, etc. These standards refer to what an organization must do to manage its processes or activities. Some Management Standards have been formed and published for implementation, whereas a large number of them are in formative process and will appear soon.

  • This is not a complete list of ISO management standards. The standards are listed in order of their number, which does not reflect their order of formation or year of publication.
  • ISO 18000 OHSMS Standard on Occupational Health & Safety Management Systems, ISO 20000 IT Service Management, ISO 20121 – Sustainable events , ISO 22000 Food safety Standards, ISO 24000 Security and Continuity Management Standards, ISO 26000 Social Responsibility, ISO/IEC 27000 Information Security, ISO 31000 Risk Management Standard, ISO 50000 series is for Energy Management Standards, ISO 55000 Asset Management Standard, etc.

ISO 50001 Energy Management Standard

  • All ISO management standards have the same structure and contain many of the same terms and definitions, which makes their adoption easier.

ISO Management standards are broadly of TWO classes. Generic Standards mean that these can be applied to any organization such as business enterprise, public project, administration or government department, whatever the product or service may be. Other Management Standards are Sector specific Standards.

ISO Management standards can also be categorized as Certifiable Standards and Requirement Standards. An organization may get a conformity Certification by a recognized agency after an audit process as specified in such a series of standards. ISO 9000, ISO 14000, ISO 18000 and ISO 22000 are management standards that allow certification. There are several other Management Standards that have no certification process, and so-called Requirement Standards. The Requirements standards, only provide guidance for implementing a management system (such as ISO 26000 and ISO 31000).

  • Conformity assessment involves a set of processes that show the product, service or system confirms to the specified requirements. The conformity assessment process has a several advantages. It gives the company or organization a competitive edge and prestige while assuring the consumers and other interested parties. The main forms of conformity assessment are testing, certification, and inspection. ISO has produced standards to help make conformity assessment activities consistently uniform across industries of the world.



Post 182  –by Gautam Shah 


Clear coatings are mainly used to show up the surface grain, colour and pattern. These however, are not always perfect or decent so need to be partially occluded or improvised. Conditioning of the substrate surfaces is needed before the application of a clear coating. The most common problems with surfaces are like:

Clear Coating over wood

Clear Coating over wood

  • uneven colour
  • unsuitable tone
  • uneven grain or pattern
  • patchy absorbency
  • uneven texture
  • bleeding or soluble constituents
  • waxy or oily deposits
  • alkalinity
  • acidity
  • galvanic sensitivity
  • moisture content and transfer

    Spectacles lenses have many different types of coatings -scratch proof, colour correction, anti glare

    Spectacles lenses have many different types of coatings -scratch proof, colour correction, anti glare / Top without coating + bottom with coating

Such problems with man-made surfaces are controllable at production level, but with natural surfaces like the wood, have to be tackled on the site.

Clear Finishes are also used where for avoidance of pigments with toxicity is required. Food packing, such as of paper, aluminium (cold drink tins), medical bottle stoppers, toys etc. require colourless coatings.

One of the oldest clear coating -wax

One of the oldest clear coating -wax

For clear coatings, to overcome the surface related problems many types of surface treatments are used. Most surface conditioners or treatments are fast drying, easy to apply, non destructive for the substrate and insoluble in the subsequent coat material.


Surface conditioners are of following types: Fillers (transparent or opaque), levelers, sealers, strainers (soluble and insoluble colourants), printed patterns, patterning tools, etching agents, bleaches, and reactants.

Staining on wood

Staining on wood

  • Fillers – Sealers are used to fill in pores so that coating material does not sink into it, and provide an even finish. Fillers generally consist of an extender, a binder and occasionally a colourant. Extenders are fine grade powder of materials like gypsum, chalk, china clay, precipitated calcium carbonate, lime, asbestine, colloidal silica, barytes and talc. Binders could be water, gums, oils, alkyds and poly vinyl emulsions. Solvent bound fillers are better compared with water bound fillers, which raise the grain or fibres of the surface. Colourants provide the necessary tint, to white extenders. Fillers, made of pigment powders, serve the purpose of filling as well as staining. Transparent fillers (low body NC lacquer, shellac, etc.) are used, not only to fill the pores, but to provide a sealing-coat to the decayable material in the grains and vessels filled with gum exhudents.
  • Stains provide a correct transparent tint to the surface. Stains are generally dye-material soluble in water, oil or solvents. Water soluble stains though of many different varieties raise the fibres and are difficult to penetrate. Oil soluble stains are heavy bodied, take longer to dry out and interfere in the subsequent coating application. Solvent soluble stains are costly, dry out immediately and may bleed residual gums and other exhudents. Stains have one important drawback that they darken the existing colour of the substrate. Where timber surfaces need to be of lighter colour, surfaces have to be bleached or toned with opaque materials.


  • Bleaching process include a treatment with hydrogen peroxide followed by an alkaline accelerator like lime, caustic soda, sodium silicate or ammonia. Bleaching affects adhesion and toughness of coating, and it also adds an amber hue to the coating on ageing.
  • Imposed patterns: On surfaces where there are very irregular grains, the patterns are screen-printed, pressed or embossed using stains. Such patterns may emulate a wood grain or just very fine mesh or lines. Staining is also done by micro spray guns, singeing, burning or carbon deposition from flames.
  • Post application treatments: Clear finishes often require some post application treatments. These are mainly burnishing and waxing. Burnishing is mainly done to NC lacquer, acrylic and melamine coatings to provide a glossy surface. Burnishing is not done to slow drying coatings, because such coatings, though are dry on outer face, take days to thoroughly dry out. Burnishing is done with a Carborundum like rubbing material with a waxy or oily base. Waxing provides a dull sheen and a protective coating. Waxing is also done to renovate old coatings. Waxing compounds also include a small amount of oils and sometime silicone materials.
    Anti reflective coating on glass

    Anti reflective coating on glass



Post 181 – by Gautam Shah 


Enamel ware Bath Tub Clawfoot_bathtub

A ceramic may be defined as a product manufactured by the heat treatment to a material or mix of materials. Ceramics are generally inorganic and non metallic solids in nature, however, small but appreciably affective metal compounds may be present in them. Ceramics are mainly crystalline, but could also be partly crystalline structured or like a glass -amorphous (non-crystalline) in nature.


Ceramic – Enamelled Hospital-ware



Ceramics are produced for many different uses. Ceramic products such as pottery, bricks etc. are formed or shaped before firing, while other ceramic products such as cement and glass are formed after firing. Some ceramics are used in their manufactured form, while others are crushed or powdered before use. Pozzolana is a natural ceramic powder, produced by the lava activity. Cements are ceramic products, where initially a ceramic called clinker is produced and then powdered. Surkhi is a burnt clay product, used to replace cement in low strength structures. Ceramics like bricks, roofing tiles, flooring tiles, cooking pots etc. can be produced cheaply at all geographic locations, from all sorts of clays. Earthenware ceramics made with very plastic or wet material are very porous. Bricks, water pots, planters etc. are conceived for this quality.


Terracotta Roofing tiles

Ceramic materials are used in toilet products such as the water closets, bath tubs, wash basins, soil pipes, etc. These items have vitreous and a non-porous surface with good gloss and excellent abrasion resistance. Similarly household tableware and oven-ware in addition have good thermal shock resistance and low thermal expansion.


Most ceramics are dielectric and except for ferrite, generally lack magnetic properties. Ceramics products’ properties like better thermal insulation, fire resistance, electric insulation and very high density make them the ideal material in electric, electronics and super conductivity field.



Ceramics unlike metals do not oxidize and are fairly stable in extreme environments, so are used for storage of alkaline and acidic substances in industries. Ceramics withstand extremely high operating temperatures, with high radiation resistance, which make them suitable for engine and turbine parts. High abrasion resistance and the capacity to withstand high temperature are two prime qualities, why ceramics are used for saturated steam and super heated gas nozzles and burner ends.


Refractory products have superior resistance to high temperatures and thermal shock, and are used in applications such as furnace linings. Ceramics’ creep resistance or ability to withstand high stress at elevated temperature is better then any material yet produced and its applications include turbine wheels, jet engines, dies etc.


Speciality ceramics are much harder than metals, and can easily cut steel and glass. Speciality ceramics because of their extremely fine-gained poly crystalline micro structures are almost free of residual pores and defects. Such materials are extremely hard and cannot easily be machined or cut, except by a laser. Toughened zirconium ceramics are used in the home as non magnetic scissors and kitchen knives, cutting tool bits, cutter edges, etc. Silicon Nitride ceramic’s engine parts can run more efficiently than do parts made of nickel based super alloys. Engine parts including combustion chamber walls, cylinder liners and heads, piston crowns and intake / exhaust parts can be made of ceramic. Ceramic bearings can operate at high speed without lubricants.


Capacitors -high-end ceramics for electric and electronics field

Body implants of ceramics in orthopaedic surgery have superior wear and erosion resistant characteristics compared with other materials. Ceramic implants for human body show not only high strength to weight ratio, but where required, these ceramics can be deliberately made porous, enabling regenerating bone to grow into and bond with the implant.


Body implant -Ceramic teeth

Ceramic air tiles consisting of an open cellular micro structure of extremely fine coated silica fibres, so loosely packed, that the tiles consist of 95% air, as lightweight as cotton wool, are used in rocketry. The ceramic tiles not only withstand temperature of 1500 C (above melting point of steel) but insulate the space module within. Micro-porous ceramics’ candles are used for filtration.


Ceramic products show various levels of glassification and depending on the raw materials used and the process of crystallization. Higher glassification levels impart better density, low porosity and in most cases better homogeneity.

Chapter Dogdae Jar Republic Of Korea Traditional

Earthenware are soft porous ceramic products fired at low temperatures (950 -1050 °C) Stoneware fired at higher temperatures (1100 -1300 °C ), show fusing of the clay body, and are fairly dense and non-porous. Porcelains are almost glass like bodies, fairly homogeneous, dense and non-porous (fired at 1200 -1,400 °C). Glass (1400 -1650 °C ) is a formation of non crystalline solid, referred to as super-cooled liquid.