Preamble
This is the fifty-seventh post in a new Art Resource series that specifically focuses on techniques used in creating artworks. For your convenience I have listed below all the posts in this new series:
Drawing Art
Painting Art - Part I
Painting Art - Part II
Painting Art - Part III
Painting Art - Part IV
Painting Art - Part V
Painting Art - Part VI
Home-Made Painting Art Materials
Quality in Ready-Made Artists' Supplies - Part I
Quality in Ready-Made Artists' Supplies - Part II
Quality in Ready-Made Artists' Supplies - Part III
Historical Notes on Art - Part I
Historical Notes on Art - Part II
Historical Notes on Art - Part III
Historical Notes on Art - Part IV
Historical Notes on Art - Part V
Tempera Painting
Oil Painting - Part I
Oil Painting - Part II
Oil Painting - Part III
Oil Painting - Part IV
Oil Painting - Part V
Oil Painting - Part VI
Pigments
Classification of Pigments - Part I
Classification of Pigments - Part II
Classification of Pigments - Part III
Pigments for Oil Painting
Pigments for Water Color
Pigments for Tempera Painting
Pigments for Pastel
Japanese Pigments
Pigments for Fresco Painting - Part I
Pigments for Fresco Painting - Part II
Selected Fresco Palette for Permanent Frescoes
Properties of Pigments in Common Use
Blue Pigments - Part I
Blue Pigments - Part II
Blue Pigments - Part III
Green Pigments - Part I
Green Pigments - Part II
Red Pigments - Part I
Red Pigments - Part II
Yellow Pigments - Part I
Yellow Pigments - Part II
Brown and Violet Pigments
Black Pigments
White Pigments - Part I
White Pigments - Part II
White Pigments - Part III
Inert Pigments
Permanence of Pigments: New Pigments - Part I
Permanence of Pigments: New Pigments - Part II
Limited or Restricted Palettes
Testing of Pigments - Part I
Testing of Pigments - Part II
Further Refinement of Pigments
There have been another one hundred and thirteen posts in a previous Art Resource series that have focused on the following topics:
(i) Units used in dyeing and printing of fabrics;
(ii) Occupational, health & safety issues in an art studio;
(iii) Color theories and color schemes;
(iv) Optical properties of fiber materials;
(v) General properties of fiber polymers and fibers - Part I to Part V;
(vi) Protein fibers;
(vii) Natural and man-made cellulosic fibers;
(viii) Fiber blends and melt spun fibers;
(ix) Fabric construction;
(x) Techniques and woven fibers;
(xi) Basic and figured weaves;
(xii) Pile, woven and knot pile fabrics;
(xiii) Durable press and wash-and-wear finishes;
(xvi) Classification of dyes and dye blends;
(xv) The general theory of printing.
To access any of the above resources, please click on the following link - Units Used in Dyeing and Printing of Fabrics. This link will highlight all of the one hundred and thirteen posts in the previous a are eight data bases on this blogspot, namely, the Glossary of Cultural and Architectural Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, the Glossary of Colors, Dyes, Inks, Pigments and Resins, the Glossary of Fabrics, Fibers, Finishes, Garments and Yarns, Glossary of Art, Artists, Art Motifs and Art Movements, Glossary of Paper, Photography, Printing, Prints and Publication Terms and the Glossary of Scientific Terms. All data bases in the future will be updated from time-to-time.
If you find any post on this blog site useful, you can save it or copy and paste it into your own "Word" document for your future reference. For example, Safari allows you to save a post (e.g., click on "File", click on "Print" and release, click on "PDF" and then click on "Save As" and release - and a PDF should appear where you have stored it). Safari also allows you to mail a post to a friend (click on "File", and then point cursor to "Mail Contents On This Page" and release). Either way, this or other posts on this site may be a useful Art Resource for you.
The new Art Resource series will be the first post in each calendar month. Remember - these Art Resource posts span information that will be useful for a home hobbyist to that required by a final year University Fine-Art student and so undoubtedly, some parts of any Art Resource post may appear far too technical for your needs (skip those mind boggling parts) and in other parts, it may be too simplistic with respect to your level of knowledge (ditto the skip). The trade-off between these two extremes will mean that Art Resource posts will be hopefully useful in parts to most, but unfortunately may not be satisfying to all!
Further Refinement of Pigments [1]
The following outline is intended for the use of painters or groups of painters who may have occasion to use pigments free from water-soluble impurities in sufficient quantity to warrant the trouble of washing pigments which are otherwise of high quality. The instructions are not given as recommendations for common use.
The impossibility of the average color manufacturer's producing pigments especially for artists' use has been mentioned in a previous post. Some of our permanent pigments contain small percentages of impurities which do not detract from their ability in common industrial applications or even in the ordinary artistic techniques, but which are undesirable in some cases where requirements are more exacting - for instance, in fresco paintings.
The restorers of Sistine Chapel work, "Daniel", assumed that the artist took a universal approach to the painting, so they took a universal approach to the restoration. A decision was made that all of the shadowy layer of animal glue and "lamp black", all of the wax, and all of the overpainted areas were contamination of one sort or another: smoke deposits, earlier restoration attempts and "painted definition" by later restorers in an attempt to enliven the appearance of the work. Based on this decision, according to Arguimbau's critical reading of the restoration data that has been provided, the chemists of the restoration team decided upon a solvent that would effectively strip the ceiling down to its paint-impregnated plaster. After treatment, only that which was painted "buon fresco" would remain.
The usual impurities in these cases will be small amounts of water-soluble salts, acids, or alkalis, which can be removed by subjecting the pigments to a few additional washings in hot water, using such simple inexpensive apparatus as employed in the laboratories of the color makers for their small-scale experimental batches. The manufacture of pigments in general does not require very complex equipment (except in the case of special furnaces for those pigments which are made at high temperatures), and jars, beakers, little tubs, and filters may be considered as miniature color factories.
Flow diagram for the production of blue pigment from kaolin.
The actual manufacture of pigments from their raw materials, however, calls for a high degree of skill and much specialized experience - an inexperienced person cannot expect to manufacture small batches of color that will equal the commercial pigments either in purity of color or in pigment properties.
Note: Professional pigment manufacture focuses on consistency, stability, and high pigment load, often involving industrial processes to create synthetic pigments, while amateur production is more focused on natural, historical, or unique colors, and the process itself is more experimental and less consistent. Professional methods prioritize durability, lightfastness, and cost-effectiveness for mass production, whereas amateur methods prioritize artistic control and customizability, often accepting lower durability or higher cost.
There are lots of blogs on the internet that show you how to make pigments from rocks that you have locally sourced.
Dry pigments are mixed with water, preferably distilled water, boiled, allowed to settle, the clear water poured off, and the procedure repeated until all the purity is dissolved and washed away; then the mixture is filtered and the pigment dried and pulverized. The washing may be done in laboratory beakers of 500 to 1000 mil capacity depending on the quantity of color needed, and an ordinary large glass funnel and folded filter-paper may be used for filtering.
G3 Buchner Funnel Filtering Kit Laboratory Vacuum Filtration Distillation Apparatus with Sand core Filtration Funnel and Erlenmeyer Flask (2000 ml).
A more satisfactory filter, however, is one assembled from a common laboratory vacuum (aspirator) pump, which is a simple affair made to be attached to a water faucet, and connected by a rubber tube to a suction-flask with a rubber stopper into which is fitted a Buchner funnel. The funnel and the suction-flask come in various sizes; the funnel is made of porcelain, and has a flat perforated surface within it, upon which is laid a sheet of coarse filter paper. After the pigment has been boiled with several changes of water, it is poured onto the filter, prerferably just before the pump has extracted all the water so that the remaining filter-cake becomes cracked and the noise of suction changes, it is washed again by pouring boiling water upon it. Then, after the pigment has been sucked free of superfluous water, the funnel is disconnected and the pigment turned out on a piece of paper and allowed to dry at ordinary room temperature or with a mild steam heat; strong heat may make it cake too hard. The washing vessel should be large enough so that the settled pigment occupies only one-fourth to one-third of its capacity, and the suction flask should be large enough so that it does not have to be emptied too often, which is incovenient.
All of this equipment is of the commonest kind and is available at any laboratory store. If beakers are used they should not be heated over a direct flame but should rest on the usual asbestos discs. If enamel pots are used, they should be of the best quality acid-proof white enamel.
It is best to know the nature and the extent of the probable impurities so that the wash water can be tested for their presence, by simple qualitative methods; acids and alkalis are detected by the use of litmus, phenolphthalein, or other indicators; and the presence of salts by adding a few drops of the usual test solutions.
Components of Vacuum Filtration Apparatus
(i) Buchner Funnel: A round or conical funnel with a flat perforated plate at the bottom. Its purpose: to hold the filter paper and support the filtration process.
(ii) Material: Usually made of porcelain, glass, or plastic. Filter Paper: Placed inside the Buchner funnel. Purpose: Separates the solid particles from the liquid. Selection: The pore size of the paper should be chosen based on the particle size to be retained.
(iii) Filter Flask (Vacuum Flask): A thick-walled flask, usually with a side arm for attaching a vacuum source. Purpose: Collects the filtered liquid (filtrate) and maintains pressure for the vacuum.
(iv) Vacuum Pump (Standard Vacuum Filtration Pump, Anti-Corrosion Diaphragm Vacuum Pump): Purpose: Creates a vacuum by lowering the pressure inside the filter flask, speeding up the filtration process. Types: Mechanical pumps or water aspirators can be used depending on the setup.
(v) Rubber Stopper: Used to form a seal between the Buchner funnel and the filter flask. Purpose: Ensures that the vacuum is maintained without leakage.
(vi) Vacuum Tubing: Connects the side arm of the filter flask to the vacuum pump. Purpose: Transfers the vacuum pressure to the filter flask to create suction.
(vii) Steps Involved in Vacuum Filtration: Setup: Insert the filter paper into the Buchner funnel and moisten it with a small amount of the solvent to form a seal. Place the Buchner funnel on top of the filter flask, securing it with a rubber stopper. Filtration: Connect the side arm of the flask to the vacuum pump using vacuum tubing. Pour the fluid to be sifted into the Buchner funnel. Turn on the vacuum pump, which creates suction to pull the liquid through the filter paper.
(viii) Separation: Solids are retained on the filter paper, while the filtered liquid (filtrate) collects in the vacuum flask.
(ix) Completion: Once the filtration is complete, turn off the vacuum pump and release the vacuum before removing the funnel to avoid breaking the apparatus.
(x) Advantages of Vacuum Filtration. Speed: Faster than gravity filtration, especially for viscous solutions or when fine particles are involved. Efficiency: Gives a more exhaustive division of solids from liquids. Improved Drying: The vacuum helps remove moisture from the filtered solids, aiding drying. Common Applications: Chemical Reactions: Used to isolate precipitates after a reaction. Purification: Evacuating undesirable solids from a fluid mixture. Environmental Testing: Filtering particulates from air or water samples. A vacuum filtration apparatus is essential in laboratory devices, offering a quicker and more efficient method for separating solids and liquids.
Dryness
In large-scale factory procedure, after washings, the moist pulp color from the filter press is broken up and spread on open trays of screening or lath and either air-dried, steam-heated, or put through a mechanical drier, according to the nature of the pigment. It is then pulverized and packed into bags or barrels; so long as it is fine, smooth powder with no tendency to form hard cakes, it is universally considered bone dry for practical purposes and is within the range of tolerance for normal painting techniques. Some artists preserve their pigments in glass jars with ground glass stoppers in order to exclude atmospheric moisture but for all practical purposes the less expensive screw cap jars and friction top cans will serve just as well. In reasonably well-conditioned rooms, they may even be stored in paper bags. When absolute dryness is required for very special cases, the pigment must be desiccated by chemists' methods. A harmful or abnormally high moisture content would be apparent by a tendency of the pigment to form itself into firm cakes or lumps.
Reference:
[1] The Artist's Handbook of Materials and Techniques, R. Mayer (ed. E. Smith) 4th Edition, Faber and Faber, London (1981).
This is the fifty-seventh post in a new Art Resource series that specifically focuses on techniques used in creating artworks. For your convenience I have listed below all the posts in this new series:
Drawing Art
Painting Art - Part I
Painting Art - Part II
Painting Art - Part III
Painting Art - Part IV
Painting Art - Part V
Painting Art - Part VI
Home-Made Painting Art Materials
Quality in Ready-Made Artists' Supplies - Part I
Quality in Ready-Made Artists' Supplies - Part II
Quality in Ready-Made Artists' Supplies - Part III
Historical Notes on Art - Part I
Historical Notes on Art - Part II
Historical Notes on Art - Part III
Historical Notes on Art - Part IV
Historical Notes on Art - Part V
Tempera Painting
Oil Painting - Part I
Oil Painting - Part II
Oil Painting - Part III
Oil Painting - Part IV
Oil Painting - Part V
Oil Painting - Part VI
Pigments
Classification of Pigments - Part I
Classification of Pigments - Part II
Classification of Pigments - Part III
Pigments for Oil Painting
Pigments for Water Color
Pigments for Tempera Painting
Pigments for Pastel
Japanese Pigments
Pigments for Fresco Painting - Part I
Pigments for Fresco Painting - Part II
Selected Fresco Palette for Permanent Frescoes
Properties of Pigments in Common Use
Blue Pigments - Part I
Blue Pigments - Part II
Blue Pigments - Part III
Green Pigments - Part I
Green Pigments - Part II
Red Pigments - Part I
Red Pigments - Part II
Yellow Pigments - Part I
Yellow Pigments - Part II
Brown and Violet Pigments
Black Pigments
White Pigments - Part I
White Pigments - Part II
White Pigments - Part III
Inert Pigments
Permanence of Pigments: New Pigments - Part I
Permanence of Pigments: New Pigments - Part II
Limited or Restricted Palettes
Testing of Pigments - Part I
Testing of Pigments - Part II
Further Refinement of Pigments
There have been another one hundred and thirteen posts in a previous Art Resource series that have focused on the following topics:
(i) Units used in dyeing and printing of fabrics;
(ii) Occupational, health & safety issues in an art studio;
(iii) Color theories and color schemes;
(iv) Optical properties of fiber materials;
(v) General properties of fiber polymers and fibers - Part I to Part V;
(vi) Protein fibers;
(vii) Natural and man-made cellulosic fibers;
(viii) Fiber blends and melt spun fibers;
(ix) Fabric construction;
(x) Techniques and woven fibers;
(xi) Basic and figured weaves;
(xii) Pile, woven and knot pile fabrics;
(xiii) Durable press and wash-and-wear finishes;
(xvi) Classification of dyes and dye blends;
(xv) The general theory of printing.
To access any of the above resources, please click on the following link - Units Used in Dyeing and Printing of Fabrics. This link will highlight all of the one hundred and thirteen posts in the previous a are eight data bases on this blogspot, namely, the Glossary of Cultural and Architectural Terms, Timelines of Fabrics, Dyes and Other Stuff, A Fashion Data Base, the Glossary of Colors, Dyes, Inks, Pigments and Resins, the Glossary of Fabrics, Fibers, Finishes, Garments and Yarns, Glossary of Art, Artists, Art Motifs and Art Movements, Glossary of Paper, Photography, Printing, Prints and Publication Terms and the Glossary of Scientific Terms. All data bases in the future will be updated from time-to-time.
If you find any post on this blog site useful, you can save it or copy and paste it into your own "Word" document for your future reference. For example, Safari allows you to save a post (e.g., click on "File", click on "Print" and release, click on "PDF" and then click on "Save As" and release - and a PDF should appear where you have stored it). Safari also allows you to mail a post to a friend (click on "File", and then point cursor to "Mail Contents On This Page" and release). Either way, this or other posts on this site may be a useful Art Resource for you.
The new Art Resource series will be the first post in each calendar month. Remember - these Art Resource posts span information that will be useful for a home hobbyist to that required by a final year University Fine-Art student and so undoubtedly, some parts of any Art Resource post may appear far too technical for your needs (skip those mind boggling parts) and in other parts, it may be too simplistic with respect to your level of knowledge (ditto the skip). The trade-off between these two extremes will mean that Art Resource posts will be hopefully useful in parts to most, but unfortunately may not be satisfying to all!
Further Refinement of Pigments [1]
The following outline is intended for the use of painters or groups of painters who may have occasion to use pigments free from water-soluble impurities in sufficient quantity to warrant the trouble of washing pigments which are otherwise of high quality. The instructions are not given as recommendations for common use.
The impossibility of the average color manufacturer's producing pigments especially for artists' use has been mentioned in a previous post. Some of our permanent pigments contain small percentages of impurities which do not detract from their ability in common industrial applications or even in the ordinary artistic techniques, but which are undesirable in some cases where requirements are more exacting - for instance, in fresco paintings.
The usual impurities in these cases will be small amounts of water-soluble salts, acids, or alkalis, which can be removed by subjecting the pigments to a few additional washings in hot water, using such simple inexpensive apparatus as employed in the laboratories of the color makers for their small-scale experimental batches. The manufacture of pigments in general does not require very complex equipment (except in the case of special furnaces for those pigments which are made at high temperatures), and jars, beakers, little tubs, and filters may be considered as miniature color factories.
The actual manufacture of pigments from their raw materials, however, calls for a high degree of skill and much specialized experience - an inexperienced person cannot expect to manufacture small batches of color that will equal the commercial pigments either in purity of color or in pigment properties.
Note: Professional pigment manufacture focuses on consistency, stability, and high pigment load, often involving industrial processes to create synthetic pigments, while amateur production is more focused on natural, historical, or unique colors, and the process itself is more experimental and less consistent. Professional methods prioritize durability, lightfastness, and cost-effectiveness for mass production, whereas amateur methods prioritize artistic control and customizability, often accepting lower durability or higher cost.
There are lots of blogs on the internet that show you how to make pigments from rocks that you have locally sourced.
Dry pigments are mixed with water, preferably distilled water, boiled, allowed to settle, the clear water poured off, and the procedure repeated until all the purity is dissolved and washed away; then the mixture is filtered and the pigment dried and pulverized. The washing may be done in laboratory beakers of 500 to 1000 mil capacity depending on the quantity of color needed, and an ordinary large glass funnel and folded filter-paper may be used for filtering.
A more satisfactory filter, however, is one assembled from a common laboratory vacuum (aspirator) pump, which is a simple affair made to be attached to a water faucet, and connected by a rubber tube to a suction-flask with a rubber stopper into which is fitted a Buchner funnel. The funnel and the suction-flask come in various sizes; the funnel is made of porcelain, and has a flat perforated surface within it, upon which is laid a sheet of coarse filter paper. After the pigment has been boiled with several changes of water, it is poured onto the filter, prerferably just before the pump has extracted all the water so that the remaining filter-cake becomes cracked and the noise of suction changes, it is washed again by pouring boiling water upon it. Then, after the pigment has been sucked free of superfluous water, the funnel is disconnected and the pigment turned out on a piece of paper and allowed to dry at ordinary room temperature or with a mild steam heat; strong heat may make it cake too hard. The washing vessel should be large enough so that the settled pigment occupies only one-fourth to one-third of its capacity, and the suction flask should be large enough so that it does not have to be emptied too often, which is incovenient.
All of this equipment is of the commonest kind and is available at any laboratory store. If beakers are used they should not be heated over a direct flame but should rest on the usual asbestos discs. If enamel pots are used, they should be of the best quality acid-proof white enamel.
It is best to know the nature and the extent of the probable impurities so that the wash water can be tested for their presence, by simple qualitative methods; acids and alkalis are detected by the use of litmus, phenolphthalein, or other indicators; and the presence of salts by adding a few drops of the usual test solutions.
(i) Buchner Funnel: A round or conical funnel with a flat perforated plate at the bottom. Its purpose: to hold the filter paper and support the filtration process.
(ii) Material: Usually made of porcelain, glass, or plastic. Filter Paper: Placed inside the Buchner funnel. Purpose: Separates the solid particles from the liquid. Selection: The pore size of the paper should be chosen based on the particle size to be retained.
(iii) Filter Flask (Vacuum Flask): A thick-walled flask, usually with a side arm for attaching a vacuum source. Purpose: Collects the filtered liquid (filtrate) and maintains pressure for the vacuum.
(iv) Vacuum Pump (Standard Vacuum Filtration Pump, Anti-Corrosion Diaphragm Vacuum Pump): Purpose: Creates a vacuum by lowering the pressure inside the filter flask, speeding up the filtration process. Types: Mechanical pumps or water aspirators can be used depending on the setup.
(v) Rubber Stopper: Used to form a seal between the Buchner funnel and the filter flask. Purpose: Ensures that the vacuum is maintained without leakage.
(vi) Vacuum Tubing: Connects the side arm of the filter flask to the vacuum pump. Purpose: Transfers the vacuum pressure to the filter flask to create suction.
(vii) Steps Involved in Vacuum Filtration: Setup: Insert the filter paper into the Buchner funnel and moisten it with a small amount of the solvent to form a seal. Place the Buchner funnel on top of the filter flask, securing it with a rubber stopper. Filtration: Connect the side arm of the flask to the vacuum pump using vacuum tubing. Pour the fluid to be sifted into the Buchner funnel. Turn on the vacuum pump, which creates suction to pull the liquid through the filter paper.
(viii) Separation: Solids are retained on the filter paper, while the filtered liquid (filtrate) collects in the vacuum flask.
(ix) Completion: Once the filtration is complete, turn off the vacuum pump and release the vacuum before removing the funnel to avoid breaking the apparatus.
(x) Advantages of Vacuum Filtration. Speed: Faster than gravity filtration, especially for viscous solutions or when fine particles are involved. Efficiency: Gives a more exhaustive division of solids from liquids. Improved Drying: The vacuum helps remove moisture from the filtered solids, aiding drying. Common Applications: Chemical Reactions: Used to isolate precipitates after a reaction. Purification: Evacuating undesirable solids from a fluid mixture. Environmental Testing: Filtering particulates from air or water samples. A vacuum filtration apparatus is essential in laboratory devices, offering a quicker and more efficient method for separating solids and liquids.
Dryness
In large-scale factory procedure, after washings, the moist pulp color from the filter press is broken up and spread on open trays of screening or lath and either air-dried, steam-heated, or put through a mechanical drier, according to the nature of the pigment. It is then pulverized and packed into bags or barrels; so long as it is fine, smooth powder with no tendency to form hard cakes, it is universally considered bone dry for practical purposes and is within the range of tolerance for normal painting techniques. Some artists preserve their pigments in glass jars with ground glass stoppers in order to exclude atmospheric moisture but for all practical purposes the less expensive screw cap jars and friction top cans will serve just as well. In reasonably well-conditioned rooms, they may even be stored in paper bags. When absolute dryness is required for very special cases, the pigment must be desiccated by chemists' methods. A harmful or abnormally high moisture content would be apparent by a tendency of the pigment to form itself into firm cakes or lumps.
Reference:
[1] The Artist's Handbook of Materials and Techniques, R. Mayer (ed. E. Smith) 4th Edition, Faber and Faber, London (1981).
