THE PALEOLITHIC WALL PAINTING

Post 677–by Gautam Shah

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The wall paintings (upper palaeolithic eras) began as a medium of expression -a ‘story’ telling exploit. It was not a decorative art for a place, but a ceremonial craft in a space. The paintings were in deep caves as well as open sites. Bhimbetka, India, sites shows human occupation for more than 100,000 years, but earliest paintings on the cave walls here date back just 30,000 years ago.

Bison Cave of Altamira

Upper Palaeolithic period began roughly around 40,000/60000 years ago and lasted through the Pleistocene ice age, which is believed to have occurred near 8,000 B.C. This period was marked by the rise of Homo sapiens and their ever-developing ability to create tools and weapons.

Bheem_Baithika_Caves_Paintings_(7)

The cave sites were difficult to access but were perhaps special and visited by several generations. The caves were deep and dark and artists worked with lamps and torch lights. The paintings were made on walls, ceilings and even floors. Many of the locations and surfaces were acutely irregular. Artists had to work in squatting lying position or use elaborate scaffolding to reach the heights. The scale of the job was stupendous. Deep cave paintings have survived, whereas open location paintings have generally been destroyed.

640px-Altamira-barlang_belseje,_nyílvános_kamra

At Bernifal in the Dordogne, the mammoths are painted 20 feet up. Some of the bulls at Lascaux are more than 20 feet long. The big cave vault at Lascaux, known as the Picture Gallery, is more than 100 feet long and 35 feet wide.

Lascaux_painting image by Prof saxx

The cave art consists of simple impromptu works as well as grand executions. The first types were perhaps executed by amateurs or apprentices, and the second by masters. To sustain projects of such scale, the master artists were helped by a retinue of assistants and the community. The assistants helped in erecting scaffolding, preparing the surface to be painted, mixing colours, devising brushes and other colour application tools, feeding animal fats to lighting torches, provisioning food and water.

Bhimbetka_Cave_Paintings

The cave artists have shown very high degree of professionalism. The compositions, understanding of the animals’ anatomical details, animals’ form, dynamism and movement, all represent a keen sense of observation, experience and discipline.

The limited choice of colours has been overcome by the masterly expression of form. There is consistent economy of line. The textural and tonal qualities do not represent the light and shade, yet suggest the depth through colour differentiation (recognizing the ‘grey tone value’). At places existing substrate textures have been exploited. The scale and distribution of objects within a composition do not follow a visual proportion system, yet prioritize the elements of the story.

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Wall painting began as a line drawing. Lines were frequently scrapped through a sharp edged tool. The etched lines perhaps helped in retaining the charcoal or soft stones rubbings. Such art works, as the primary responses were impressed on whatever interior or exterior surfaces that were available. However, it was realized that more permanent work can only be created in a protected space. The caves space and its environment stimulated a spiritual experience for the portrayal. The spaces must have been favoured by several generations, as some of the paintings have been modified repeatedly over thousands of years. The earliest works are refined compared to later works or modifications.

Paintings_from_the_Chauvet_cave_(museum_replica)

There is nothing to suggest that the art was a setting of a ceremony. There is no depiction of a sacrifice, or a master of ceremonies like a priest, sorcerer or a witch-doctor. The paintings also have no images of the surrounding terrain or the vegetation of the time.

Bison-Cave-Painting-Altamira-Caves

The palaeolithic wall art consists of three main categories of subjects: animals, humans and signs (abstract or unexplained). The animal figures are the most detailed and naturalistic representations, but drawings of humans are rare and perfunctory. ‘In the case of Chauvet, predatory or dangerous animals dominate, while in Lascaux the main representations are of large herbivorous mammals’. At caves across various geographic locations the animals include: woolly rhinoceros, lions, bison, horses, aurochs, bears, reindeer, wisent, and giant deer and hyenas. At places species which were then extinct (as per the time dating technology), are also painted. Some of the most common species such as the reindeer do not find any representation, though bones have been found in the cave. The wall art also includes prints of spray painted hands, with abstract interconnecting lines.

Lascaux,_Megaloceros

The abstract signs are said to be representing the perception of night skies, of stars etc. Some forms of visual effects of movement or vibrancy (experienced in limited illumination) were perhaps included by use of florescent dyes, and slightly shifted images.

MATERIALS and TECHNIQUES

SantaCruz-CuevaManos-P2210651b

Wall art of upper Palaeolithic age in the early phase did not have any surface preparation except scrubbing off the loose particles and dust. Selected surfaces were away from flowing or leaching water. Early phase drawings were done in line work with charcoal, but compared to this the carbon black, a deposit over an animal fat burning lamp had better binding and colour saturation. Lines were also scratched or etched by a sharp tool and done over with a black colour. Scratching the surface also ensured better colour retention. Later renderings (filling up the colour) with red ochre (Iron oxide from Haematite) and black was done. In the later phase (25000/20000 BC) other colours such as yellow and brown were added to the palette.

PanneauDesLions(CentreGauche)RhinocérosEnFuite

In the initial phase dry colours were rubbed over the surface. In the later phase colours were ground with water and additives like blood, urine, eggs and animal fats. The additives improved the bonding, increased the viscosity (to prevent run off the surface) and reduced the drying time (allowing application and rendering effects). Learning also included: how to prepare intermediate shades (orange and browns), prevent algae like growth, avoid colours that fade over an age and moisture bleeding of colours and additives. Colours were mixed Calcium containing water or nodules to improve fixing.

caveart

The colours were ground by rubbing them over a rough surface, and also through pestles and mortars. At Lascaux, some 158 different mineral fragments were found. Shells of barnacles and human skulls were used as containers for ground pigment pastes. Colour was applied by brushes, twigs and fingers. Colours were also put on by spraying through mouth and blow pipes made from bird bones, and by daubing with hands, fibrous pads and soft skins. Colours were sprayed over hands as the stencils to perhaps mark the participation or visitation.

altamira Hand spraying but of post original work period

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BLOGS LINKS about PERCEPTION

Post 652 -by Gautam Shah

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These are my select few 91+ blogs (out of nearly 850 placed on my 4 blog sites) written over last 4 years, now compiled under a common theme ‘Space Perception’ with following sub sections.

      0  New series of Lectures (Four) on Perception

  1. SPACE PERCEPTION
  2. ILLUMINATION
  3. MOVEMENT, BALANCE
  4. OPENINGS SYSTEMS
  5. GLASS
  6. GRILLS, TRELLIS, CURTAINS
  7. SOUND and NON VISUAL
  8. OBJECTS, SURFACES, COLOURS, PATTERNS
  9. REALITY, MAKE-BELIEVE

 

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0  New series of Lectures (Four) on Perception

0.1 SOME SOUND BITES -Space Perception -I

https://designacademics.wordpress.com/2018/02/12/some-sound-bites-space-perception-i/

0.2 STRATIFICATION of VISION

https://designacademics.wordpress.com/2018/03/02/stratification-of-vision0.2 /

0.3 PERCEPTION of SPATIAL FIELDS -ILLUMINATION

https://designacademics.wordpress.com/2018/03/11/perception-of-spatial-fields-illumination/

0.4 MULTI NODAL PERCEPTIONS of OBJECTS in SPACE

https://designacademics.wordpress.com/2018/05/14/multi-nodal-perceptions-of-objects-in-space/

 

 

1 SPACE PERCEPTION

1.1 PROCESS of PERCEPTION

1.2 PROCESS of PERCEPTION part-I

1.3 SPACE PERCEPTION -through seeing, hearing and touching

1.4 SPACE PERCEPTION – Issues for Design -4

1.5 SPACE PERCEPTION

1.6 SPATIAL DEFINITIONS

1.7 SENSING OBJECTS BEYOND THEIR SIZE MEASURES

1.8 SPATIAL DEFINITIONS

1.9 SPATIAL DISTANCING and BEHAVIOUR

1.10 DISTANCING in SPACE

1.11 SPACES SIZES and SHAPES

1.12 SMALL SPACES and LARGE SPACES

1.13 REACH in SPACE

Scaffold Building Manhattan New York City Taxi

2 ILLUMINATION

2.1 CONTRAST EFFECT – PERCEPTION

2.2 PERCEPTION of SPATIAL FIELDS -ILLUMINATION

2.3 DAYLIGHTING

2.4 DAY-LIGHTING – in Interior Spaces

2.5 DESIGN CONSIDERATIONS for DAYLIGHTING

2.6 SPACE PERCEPTION and ILLUMINATION

2.7 DAYTIME INTERIOR ILLUMINATION -REALITY and PERCEPTION

2.8 INTERIOR ILLUMINATION through DOORS

2.9 WINDOW LOCATION and NATURAL LIGHTING

2.10 LE CORBUSIER and ILLUMINATION

2.11 COMPARING WINDOWS of FLW, LC and Mies

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3 MOVEMENT, BALANCE

3.1 MOVEMENT and BALANCE – Issues for Design -5

3.2 PERCEPTION of BALANCE and MOVEMENT

3.3 BALANCE in DESIGN – Part 1

3.4 BALANCE in DESIGN – Part 2

3.5 VISUAL PERCEPTION of MOVEMENTS

3.6 PERCEPTION through SCALES and CONVERSIONS -Issues or Design -3 

Landscape

4 OPENINGS SYSTEMS

4.1 LEVELS of OPENINGS

4.2 DESIGNING OPENINGS

4.3 CLASSICAL WINDOW FORMS

4.4 ARCHITECTURAL WINDOWS and VISION in-out

4.5 ARCHITECTURAL WINDOWS and the MEANING

4.6 ARCHITECTURAL WINDOWS and MECHANICS of VISION

4.7 MEANING of a WINDOW SILL

4.8 THIRD DIMENSION of OPENINGS

4.9 LANTERNS in ARCHITECTURE

4.10 CLERESTORY OPENINGS

4.11 SKY LIGHTS

4.12 ROOF LIGHTS

4.13 SHOP WINDOWS

4.14 SHOP WINDOWS – SHOP FRONTS – DISPLAY WINDOWS

4.15 FRAMING of OPENINGS

4.16 MASKING of OPENINGS Part -III -Framing

4.17 MASKING of OPENINGS Part -II

4.18 MASKING of OPENINGS Part -I

Eating_Alone

5 GLASS

5.1 GLASS in ARCHITECTURE -1

5.2 GLASS and PERCEPTION

5.3 GLASS in WINDOWS – Part • I

5.4 GLASS in WINDOWS – Part • II

5.5 COLOURED GLASS

Fixing Metallic Transparency Glass Front Metal6 GRILLS, TRELLIS, CURTAINS

6.1 CONTEXT -Issues for Design -12

6.2 ROOFS 3 -Skyline and Silhouette

6.3 HOLISM and DESIGN

6.4 TRELLIS

6.5 GRILLS

6.6 CURTAINS

6.7 TRANSLUCENCY for CURTAINS

6.8 SHEER FABRICS and CURTAINS

6.9 SHEER FABRICS and CURTAINS-2

6.10 NON SILK SHEER FABRICS and CURTAINS

6.11 WEIGHT and TRANSLUCENCY of fabrics for curtains

6.12 SHEER FABRICS

Religious Kneeling Worship Pray Prayer Church

7 SOUND and NON VISUAL

7.1 SOUND

7.2 SOUND, SPACE and PERCEPTION

7.3 PERCEPTION of SOUND and SPACES

7.4 SPACE and SOUND REVERBERATION

7.5 SOUND and NOISE MANAGEMENT

7.6 HEARING and interior spaces

7.7 ACOUSTICS in SMALL SPACES

7.8 SOUND and SMALL SPACES

7.9 SPACE PLANNING and NON VISUAL CUES

7.10 NON VISUAL LANGUAGE -Issues for Design -6

7.11 LANGUAGE EXPRESSION and SOUND PERCEPTION

wuzhen-1643267_6408 OBJECTS, SURFACES, COLOURS, PATTERNS

8.1 OBJECTS in SPATIAL FIELDS -Issues for Design -14

8.2 COLOURS -Perception and Expression

8.3 COLOURS and BUILDINGS

8.4 FLOORINGS

8.5 FLOORING COLOUR

8.6 FLOORINGS IN INTERIOR SPACES

8.7 PERCEPTION of SURFACE FINISHES

8.8 GLOSS

8.9 TEXTURES and MATERIALS

8.10 JOINTS in SURFACE FINISHES

8.11 MOSAICS

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9 REALITY, MAKE-BELIEVE

9.1 SOLIDS and VOIDS -issues for Design -13

9.2 AUGMENTED REALITY

9.3 SPACES and REALITY

9.4 MAKE-BELIEVE in INTERIOR DESIGN

 

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WATER COLOURS

Interior Design Assist

640px-set_of_watercolor_paints_-_ariel_waldman Water colours > Wikipedia image by Ariel Waldman from Munice

The distinguishing characteristic of water-colour painting is its translucency. The surface of the paper is visible through the thin water-colour pigments. It creates a veil-like effect that is very distinctive from the heavy and opaque painting in oil. Water Colour paintings have been created on papyrus, bark papers, plastics, vellum or leather, fabric, wood, and canvas.

brushtypes Water colour brushes Wikipedia image by Vinegarten en wiki

Water-colour paints are produced by mixing dry powdered pigments with gum arabic (a natural gum of acacia trees). Solid water-colour cakes can be dissolved in water and applied to paper with a brush. Although water-colour is a relatively modern type of paint, but various water-based paints systems have been used throughout the recorded history. Water colours are usually transparent and seem of pure hue because the pigments are applied in a relatively…

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COLOUR MODELS (RYB)

Post 530  by Gautam Shah

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RYB MODEL Subtractive colors

The search for ‘truest’ or ‘purest’ colour has been a story of revelations. Some of the purest forms of colours have been available in nature, as flowers, body colours or spots over insects and birds. These were sought in applicable forms such as pigments and juices or dyes. It was realized from very primitive times that both the forms have distinctive applications. Pigments are good for wall-arts and juices or dyes are good for body colouring, fibres and leathers. Beyond this it was also known that pigments were comparatively opaque in comparison to nearly transparent juices or dyes. Primitive age craftspeople had typical understanding that very ‘pure colours shades’ were less lasting than slightly compromised shades. This realization was due to the fact that oxide and natural pigments were longer lasting or non-fading. A ‘richer’ shade of colour was sought by methods of purification or concentration through separation, grinding, washing, floatation, sieving, calcination or sintering.

Centre Le Corbusier, Zurich Wikipedia image by Author Absinthe.

Since prehistoric period it was also clearly known that richness of the colour lies in the contrast it creates with the nearby colour. Such an understanding of colour value is known only to the actual user of the colour and not to lay persons who can philosophize the effect. Realizations are not necessarily visual percepts. Through such attempts of definition first theories of colours began to emerge. Greek philosopher Aristotle related colours (as maintained in De colouribus) to the four elements: air, water, earth and fire. But then he was not a visual art practitioner.

Aristotelian world of Colours Land Sky Water Wikipedia image by Author Ikhlas Qassmi 13336

“For air and water are naturally white in themselves, while fire and the sun are golden. The earth is also naturally white, but seems coloured because it is dyed. This becomes clear when we consider ashes; for they become white when the moisture which caused their dyeing is burned out of them; but not completely so, for they are also dyed by smoke, which is black. In the same way sand becomes golden, because the fiery red and black tints the water. The colour black belongs to the elements of things while they are undergoing a transformation of their nature”. -Aristotle’s realizations of colours.

Since Aristotle’s time such ‘subjective realizations’ have found little favour with the art painters. Their triad of colours was of Red-Yellow-Blue of pure colours or un-creatable shades. But for many years, black and white remained baffling ‘colours’. One could mix few colours to match a ‘near-black’, but the same was not possible for white or ‘near-white’. The ‘disappearance of colours’ on a flying wheel and perception a white was not yet logically connected to this perplexity. It had to wait for Newton to explain it. Many painters before 1600s have written about creating and using colours, their ability to consistently reformat the same colour and also their inability to reformat the same shade in spite of all care and documented formulations. Describing a colour was even harder than creating it. The writings fail on how to state a colour shade. Colours have had only metaphoric interpretations.

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ColorTriad

Colour chart by Franciscus Aguilonius (1567-1617)

The Red-Yellow-Blue colour triad was the painters’ logic of defining the colours as per the visual experience. Franciscus Aguilonius (1567-1617) a physicist disputed Aristotle’s theory or rather the philosophy of colours. He devised a better method of identifying and arranging the colours. Colour arrangement was of placing 5 colours White – Yellow – Red – Blue – Black, at the bottom, and mixes of these forming the riser. He included the Red, Yellow and Blue which became the forerunner of other systems that function in a similar way. This was a chart, and not a colour wheel.

Wikipedia image > Goethe’s symmetric colour wheel with associated symbolic qualities (1809)

 

Runge_Farbenkugel

From Wikipedia

Aron Sigfrid Forsius (1611), a Finnish born astrologer, priest and neo-Platonist, and contemporary of Franciscus Aguilonius, derived a drawn colour arrangement with five main colours: Red, Yellow, Green, Blue and Grey, all placed for their affinity to Black or White. This, however, was going to change some 60 years later. In 1672, Newton showed the optical quality of colours, as a spectrum of seven colours. This was very different from earlier attempts of visual gradations of colours. This interpretation was challenged, by Goethe in the ‘Theory of Colours’ (1810). For him it was important to understand the human reaction to colour, compared with Newton’s science supported explanation. But at that time there were few takers for it. Newton first divided the spectrum in five main colours red, yellow, green, blue and violet but later included orange and indigo, to analogize with the seven notes in a musical scale, and perhaps the solar system, and days of the week.

A linear representation of the visible light spectrum wikipedia image by Author Gringer

Richard Waller in Stockholm published a list of 119 colours arranged from ‘dark to light shades’ in seven columns each topping with a basic colour. Jacob Christian Schäffer a German a natural historian and inventor wanted some standard format (Table of physiological colours, mixed and Simple, in 1686) that would permit unambiguous descriptions of the colours of natural bodies. This was the beginning of naming, identifying and graphically specifying the colours.

probably Claude Boutet’s 7-color and 12-color color circles Wikipedia image

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BLACK Part – II

Post 517  by Gautam Shah

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Black soot covered walls Almeida Júnior – Country Kitchen – oil on canvas 1895

Black is one of the prime colours, used by humans. Red, though is very vivid and fascinating colour in the history. Red and Black have ethereal connection, and both seem almost indistinguishable in monotone perception. This was one of the reasons that in the black-white cinema era, heroines avoided red dresses and lipsticks. The infamous Psycho shower scene of blood, was shot with not red liquid but most palatable chocolate syrup. The BW movie Jezebel (1938 with cast Bette Davis, Henry Fonda, George Brent), based on Brilliant scarlet dress (outrageous) the heroine wore, was actually Brown in colour. It was a well-deliberated move. Was this the story of red colour in dark dimly lit cave paintings of Paleolithic age? Could they have perceived black from the red, when both of which were extensively used. Paleolithic painters had several sources of black, such as wood charcoal, bone charcoal, manganese oxide, in addition to the tonal variations caused by the surface binding mediums like water, tallow, fish oil, eggs, wax etc. The hue variations were caused by the direction, and intensity of the lighting torch or fire used to see the paintings.

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Black is the ‘strongest colour’ (or in scientific language the most remarkable absence of all colours of the spectrum). It was used as draft line of the figure, for highlighting the silhouette of the figure, in few instances for defining the colours’ edges, for containing and bounding the running colours of low viscosity. Paleolithic painters used black (and also other colours such as ochres and red oxides) to shade the artwork for tonal effects. The tonal variations served the purpose adding a depth dimension, for emphasizing the important segments of the composition, and only in later periods for light shading. Light shading with subtle use black was to indicate the direction of the source and often to the root of the magical power.

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Carbon Black with high ash content

Carbon Black Pure

Black has been a great additive to tone up (or down) other colours. It, however, is a very strong shade tinter, even better than the whites available in early periods. Black, true to its nature, would reduce the brightness (visual impact) of the colour, compared with the addition of the white. Black added colours contribute depth to the colour. By the time of Iron age, the technique of adding black to vary the tones became much less popular. This was mainly due to the availability of multiple shades of ochres, oxides, etc. Blacks of different origins were added to whites of various types (such as calcium carbonate, barytes, gypsum) to achieve vast range of greys for use in mural paintings.

Red Black combination in Cave Art > Reproduction of a bison of the cave of Altamira Wikipedia image by Author Rameessos

The most difficult part was how to reduce or alter the tonal quality of black? Addition of white reduced it to grey shade, a completely alienated entity of black. In painting, the lightness of a shade was adjusted through mixture with white or black, but now by adding a colour. This was done first by using black of different origin, than by mixing very dark colours such as red oxide, black iron oxide, dark amber, and by adding low opacity ‘white minerals’. When yellows, reds and oranges are mixed with small amounts of black, it can cause a change to very a different shade.

Greys by avoiding the Black >> Gare Saint Lazare, 1877 Claude Monet (1840–1926)

Blacks, greys and other shades shift with the addition of black, often to a level that scared many seasoned artists and crafts-persons. The scare was more forbidding due to the metaphoric association with Gods, human behaviour and varied perceptual interpretations. Blacks of all origins, however, had one positive advantage that this was non fading or non destructible colours. Their tinting strength was fairly good and the perceptible shade was just ‘black’ with very few sub-variants. But its effect on other colours after mixing or through sheer proximity was extremely profound.

Impressionists avoided use of Black > Auguste Renoir – Dance at Le Moulin de la Galette

Art teachers, have been telling their apprentices, juniors and students to keep away from black. The same advise still holds true even today. If you are an interior designer, architect or builder, do not play around with black, unless you have the capacity for course correction or complete redo. Blacks are very opaque, and have a very high tinting strength, so a small amount can cause devastating effect. The small amount is very ill-defined and difficult to measure a term, and thoroughly mixing it into a larger mass without industrial equipment, an impossible task.

rosa-1911660_640Artists can mix few darker colours and get away with a ‘black’ like effect such as ultramarine blue and burnt umber can do it. The impressionists remained away from black, and preferred to devise the ‘black effect’.

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UNDERSTANDING LACQUERS

Post 498 –by Gautam Shah

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Cosmetic Box

In early 1920 Lacquers were considered industrial coatings, mainly used by White-goods and Automotive industry. Earlier to this period a Lac or Shellac coatings were wood craft finishing techniques and material. Industrial age lacquers were favoured due to their fast drying and non-yellowing properties. Clear Lacquers were increasingly replacing tin as MS sheet coating for food packing but were found suitable for aluminium sheets packing such as collapsible tubes and canisters. Lacquers were also used for the nail polishes and as hair fixing sprays. These lacquers as the name suggests were not made of natural Lac or shellac but from Nitro Cellulose. The lacquers needed thinners of various types for different application technologies and seasons.

Lacquer Paint Pic from Wikipedia by Author Victorgrigas

Oil paints based on Alkyd resins or GP Enamels need thinner of single solvent material such as Genuine turpentine, Mineral turpentine and in few instance Naphtha or superior grades of kerosene would work. These solvents singly can work for all application needs and for cleaning-washing post-painting work. With alkyd-based paints, a resin is the film-forming component. It is reduced in viscosity during the manufacturing and later during application. The requirements of solvent-s differ according to ‘length of the resin’ (which designates the proportion of oil versus other modifying-polymerizing agents, such as typically a phthalic anhydride). Short-oil length resins may require stronger solvents. A solvent that dilutes the viscosity alone may not achieve application level of viscosity. Some type carrier or diluent solvents are required which acting as a ‘carrier’ material help achieves application level (such as spraying) viscosity. The carrier solvents evaporate fast before the chain linking (and so film forming-drying) process starts at ambient temperature, raised or baking temperature or through a catalyst enabled reaction.

Wood Brushing Lacquer Pic from Wikipedia Pic by Author Mk2010

The word Lacquer has become a misnomer. A Lacquer in nominal usage means a coating system that is fast drying, tougher and non-yellowing. All lacquers, however, are not NC (nitro-cellulose) lacquers. Other Lacquer coating systems formulations are based on Acrylic resins, Amino resins, Urethane and epoxy systems. NC lacquer dries with evaporation of solvents, at ambient temperature or often in warm chambers. Other formulations require baking-stoving environments or have two-pack system (a catalyst and paint mixed just before application). A NC lacquer film can be wetted-dissolved after drying (such as Nail-polishes of pre 1965 era) by a thinner, and are called ‘non-convertible systems’ (product that does not get chemically converted into something else). But newer generation-lacquers cannot be dissolved or removed easily after drying, and are called ‘convertible systems’ (product that gets chemically converted into something different).

Box Lacquered

Lacquer Nail Polish Pic through Wikipedia -Source http://www.flickr.com/photos/zitona/4733601645/ by Author » Zitona «

All types of Lacquers, convertible or non-convertible products require very specific type of thinner. A company that formulates the paint system, for reasons of Patent knowledge, may not reveal the exact formulation. So it is very necessary to use the thinner specified by the manufacturer. A thinner is a combination of different solvents. There are two important considerations, action of dissolving and diluting (acting as a carrier), and evaporation rates of the solvents. A Lacquer system may need as much as 75% or more thinners for spray like application. But after the deposition on the surface, it does not require such low viscosity. So some solvents (usually diluent or carrier) begin to evaporate very quickly. Some other slower evaporating solvents, allow time for film to level out.

640px-Hair-Spray-Painting-6415.jpg

Lacquer coated Brass

A lacquer-thinner is a combination of solvents of basic Five groups. First group consists of latent solvents like Toluene, xylene and naphtha. The other three groups are of active solvents such as, ketones, esters, glycol ethers. Alcohol, though a latent solvent, in combination with other solvents plays an active role.

Lacquer thinners are affected by the weather and process of application. A normal thinner works for average temperature-moisture conditions. For very wet, windy weather and for brushing or manual polishing with a cloth bundle, reduced the rate of evaporation achieved by adding or using a ‘retarder thinner’. For spray like application, an accelerated rate of drying is possible and for this accelerator or fast lacquer thinners are used. Spray applications require more and faster drying thinner compared to wood lacquers that require less and slow drying thinner.

Channapatna-toys

1280px-Sankheda_furnitureChairs_of_3_piece_set

Shellac finishes were the first true clear coatings. Shellac is an insect exudate known as stick lac. Stick-Lac is refined to remove impurities and lighten its colour. Button-Lac is a manually purified is of darker colour, while machine purified shellac is often dewaxed and de-colourized. Shellac is soluble in methylated spirit or alcohols. Sankheda furniture and Chinese lacquer items are examples of shellac coatings. Shellac is a very effective coating material even in very thin viscosity, as a result its penetration and filling capacity is excellent. It is eminently recoatable so a very level and glossy surface is possible.

640px-Burmese_lacquerware.JPG

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PAINTING WHITE – 2

Post 485  –by Gautam Shah

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402px-Van_Doesburg_and_Rietveld_interior_1919

During 1930-50s Paint shops used to offer Oil-bound Distempers (OBD) and combination of Zinc pastes and double-boiled Linseed oil, for household painting. These were mixed with pigment pastes for shade creation. Post 1950s ready mixed oil paints or General purpose enamels (GP) became popular. But than paints’ shops had to stock several tins of different measures, for each of the shades and varieties (oil paints, distemper paints, flat and egg-shell plastic paints). And to match a desired shade, it was necessary to buy small bottles or vials of concentrated pigment pastes called tinters and top up an available shade or create one from a white.

Paint Shop of earlier era

There were two whites available, a ‘super-whitewith some form of ‘optical whitener or brightener, an ‘opacifier’ or colourants like blue or violet, and pure stuff called base-white, without any additives. Few lay people were aware of the later variety, or considered it to be some inferior stuff due to its less romantic name (super white versus base-white), and discounted price.

Zinc paste-based paints and General purpose enamels had linseed oil or its alkyd resins as the chief film forming material. The linseed has a tendency to oxidize and turn yellow over the age. This began to change due to strong demand from manufacturers of white-goods (consumer goods painted white such as ovens, fans, washing machines, refrigerators, etc.) for long-term non yellowing finishes. This led to use of non yellowing oils for resins, and new generation formulations of Urethane, Amino resins and epoxies. The same innovations began to percolate to home-paint markets. From 1960s Plastic polymer-based emulsion paints (called Latex paints in USA) began to be available. This offered non-yellowing white paints.

Shade Card

Titanium Dioxide as a whitest pigment had few technical problems of paint formulations, but these were initially solved with use of Zinc and Lithopone as additives. Oil paints in glossy and flat varieties, and Plastic Paint with, sheen, egg-shell-matt and flat varieties now were offered as one or two coat systems. This high hiding-covering was due to excellent pigment grinding-dispersion in machines like attritors that replaced ball and roller mills.

United States Capitol west front

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Paint markets are now radically changed. Paints manufacturing companies depend on shops to match the colour shades. The shades are created from basic, and few vials of ground pigments, which inject exact-micro quantity of colours into range of base formulations. The base formulations, include nearly clear to several types of white paints. White bases have natural shades of white pigments, and some have whitening-opacifiers. A white base is used for light tints, but not more than 100 ml paste can be added for darker shades to avoid loss of gloss or the effect on drying time. A neutral, pastel or mid-base contains lesser quantity of white pigment and is used for creating darker colours. And a clear base is used (it may contain white powders of low refractivity or extenders, but is free of high refractivity white pigments), for very deep colours. Some manufacturers use this base to add little sheen to matt paint.

Whites are affected by surroundings and show many variations

Whites are affected by smallest amount of additive colourants. These colourants may come from residues of earlier colour in brushes or rollers, any loose particles on the surface to be painted and thinners (solvents and water). Some additive colourants, if not thoroughly mixed, begin to darken the colour shade over brushing or rolling. Extra ordinary care is required in selecting, buying, mixing and using, white and ‘off-white’ shades. Shops have a file of colour shade cards, which are rarely fresh. The shade card viewing must be done in natural light, as it is affected by the surroundings and type of illumination. Shop computer calibrated and mixed shades, are not necessarily exactly right as per the shade card or as per your need.

A colour shows many variations at different angles of viewing and so colour matching must be done perceiving it from as many positions > Pic by https://www.flickr.com/photos/horiavarlan/4271993197

One of the best ways is to buy a small trial pack, and apply it on two different walls (preferably at right angles), at the site location. Once a right shade is achieved, leave some quantity (see the next paragraph) in the trial pack for master batching and matching.

HOW to mix a white shade with very light tinge of other colours at home? Buy the most appropriate white-base out of several ones available at a paint shop (usually 2-6 varieties). Now separately mix the concentrated tint to small quantity of white-base, with shade as close matching to your desire. Such faint tinges of colours are very difficult to visually perceive. So place a drop of experimental mix over the quantity left in trial pack. Your shade will be either darker or lighter, but easily perceptible.Mixed Whites

Most plastic emulsion paints now have a ‘Thixotropic’ compound, which gives a heavy, butter like false viscosity to the paint, to prevent separation or settlement of heavier phases or solids. Stirring is required to reconvert the stuff to a temporary liquid phase. Plastic paints come with good odours, to suppress the unpleasantness of paints, but one need not judge a paint on that count.

Color Blue Church Terrace Architecture White

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