Preamble
This is the fifty-sixth post in a new Art Resource series that specifically focuses on techniques used in creating artworks. For your convenience I have listed all the posts in this new series below:
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
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!
Testing of Pigments - Part II [1]
Draw-Outs. Another method for comparing the relative color and strength of artists' oil colors, which may be used on prepared tube colors, as well as on dry pigments, is the one which is used by the printing ink trade, which values pigments for their transparent undertones as well as for their top tones or body color. The dry color is weighed out and rubbed up with oil, as in the previous account (see last months blog in this series), or samples may be squeezed out of two tubes of prepared oil colors and placed side by side at the end of a wide flexible wall-scraper.
As in the above figure, the handle is grasped in such a manner that when the blade, loaded at the tip with the two dabs of color, is drawn across a pad of white bond paper, pressure can be controlled. The first part of the stroke is light, and a thick layer is thereby transferred to the paper; after one-half to one inch (1.27 to 2.54 cm) of this has been applied, the knife is held vertically, and with a firm, scraping pressure it is drawn across the paper with a rather rapid stroke, which will produce a thin staining on the paper. By holding this drawn-out against the light, comparison of the two samples is easy, and minute differences in color, clarity, strength, hiding power, etc., may be almost quantitatively estimated. Try this with alizarin lake oil color of known high quality, and a students' grade color made of genuine pigment let down with inert material. An experienced technician can judge the percentage difference or variation quite accurately.
“Scottish Wildcat” oil on canvas panel. Painted with artist-grade paints.
"Blue Dreds" oil on oil-primed panel. Painted with all student paints.
Volumetric Method. The evaluation of artists' paints on the basis of weight is not rational. Artists use their materials by volume rather than by weight and a direct volumetric method of comparing the relative tinctorial strengths of pigments is better suited to the artists' purposes. Also artists will more often wish to compare ready-made oil colors than dry pigments. In a future blog post in this series a standard method will be decribed for the determination of the relative tinctorial strengths of oil colors by volume. Simpler, but less precise methods using less precise devices, such as kitchen measuring spoons, can be devised. The ratio should be 10 parts to 1 part white oil color, and for the very powerful colors, 20 to 1.
Kitchen Measuring Spoons.
Dry Color. Dry pigments are compared by placing small piles side by side, covering them with paper or cellophane, and pressing the paper down firmly and smoothly with a palette knife. When the flattened surface of the combined piles of color is viewed in daylight, the line of demarcation and any differences in shade is easily seen. A drop of turpentine placed where the pigments join will bring out the variation in tone with white or inert pigments.
Palette Knife Set.
Fading. Artist oil colors are tested for color stability in direct outdoor sunlight. Tints do not resist this severe accelerated test to the same degree as do straight pigments, so the original American Paint Standard tests were run in 85% reductions with zinc white as well as in full strength. But since the properties of the accepted pigments are well known, and since any samples that pass the full-strength tests would be acceptable and would not be expected to fade indoors in any reduction, full-strength test alone were deemed adequate. Water colors on rag paper may be exposed in a photographers printing frame in an unobstructed south window (USA), with a strip of black paper or cardboard protecting part of the painted paper for comparison. All such accelerated tests are extremely stringent and provide a wide, safe margin over centuries of actual indoor exposure to diffuse daylight and artificial light.
Yellowing. The accelerated test described in last month's Art Resource post is also used for yellowing.
Hansa yellow light lightfastness samples (2004). After 800+ hours of sunlight exposure: (left to right) Utrecht, Sennelier, Daniel Smith, Schmincke, Da Vinci.
Dyes and Lakes. No paint pigments should be soluble in oil, water, or the volatile solvents. To test for insolubility, dust or blow a small amount on wet white blotting paper. Any solution will be immediately apparent. The same filter paper test is used with soluble dyestuffs to distinguish between single dyes and mixture of dyes.
Lighting. Color comparisons should be viewed in daylight; most of the artificial daylight lamps are unsatisfactory substitutes. Although an even north light (USA) is preferable, in the greater number of cases, direct bright sunlight is sometimes useful in examining blacks and other very dark colors.
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-sixth post in a new Art Resource series that specifically focuses on techniques used in creating artworks. For your convenience I have listed all the posts in this new series below:
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
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!
Testing of Pigments - Part II [1]
Draw-Outs. Another method for comparing the relative color and strength of artists' oil colors, which may be used on prepared tube colors, as well as on dry pigments, is the one which is used by the printing ink trade, which values pigments for their transparent undertones as well as for their top tones or body color. The dry color is weighed out and rubbed up with oil, as in the previous account (see last months blog in this series), or samples may be squeezed out of two tubes of prepared oil colors and placed side by side at the end of a wide flexible wall-scraper.
As in the above figure, the handle is grasped in such a manner that when the blade, loaded at the tip with the two dabs of color, is drawn across a pad of white bond paper, pressure can be controlled. The first part of the stroke is light, and a thick layer is thereby transferred to the paper; after one-half to one inch (1.27 to 2.54 cm) of this has been applied, the knife is held vertically, and with a firm, scraping pressure it is drawn across the paper with a rather rapid stroke, which will produce a thin staining on the paper. By holding this drawn-out against the light, comparison of the two samples is easy, and minute differences in color, clarity, strength, hiding power, etc., may be almost quantitatively estimated. Try this with alizarin lake oil color of known high quality, and a students' grade color made of genuine pigment let down with inert material. An experienced technician can judge the percentage difference or variation quite accurately.
Volumetric Method. The evaluation of artists' paints on the basis of weight is not rational. Artists use their materials by volume rather than by weight and a direct volumetric method of comparing the relative tinctorial strengths of pigments is better suited to the artists' purposes. Also artists will more often wish to compare ready-made oil colors than dry pigments. In a future blog post in this series a standard method will be decribed for the determination of the relative tinctorial strengths of oil colors by volume. Simpler, but less precise methods using less precise devices, such as kitchen measuring spoons, can be devised. The ratio should be 10 parts to 1 part white oil color, and for the very powerful colors, 20 to 1.
Dry Color. Dry pigments are compared by placing small piles side by side, covering them with paper or cellophane, and pressing the paper down firmly and smoothly with a palette knife. When the flattened surface of the combined piles of color is viewed in daylight, the line of demarcation and any differences in shade is easily seen. A drop of turpentine placed where the pigments join will bring out the variation in tone with white or inert pigments.
Fading. Artist oil colors are tested for color stability in direct outdoor sunlight. Tints do not resist this severe accelerated test to the same degree as do straight pigments, so the original American Paint Standard tests were run in 85% reductions with zinc white as well as in full strength. But since the properties of the accepted pigments are well known, and since any samples that pass the full-strength tests would be acceptable and would not be expected to fade indoors in any reduction, full-strength test alone were deemed adequate. Water colors on rag paper may be exposed in a photographers printing frame in an unobstructed south window (USA), with a strip of black paper or cardboard protecting part of the painted paper for comparison. All such accelerated tests are extremely stringent and provide a wide, safe margin over centuries of actual indoor exposure to diffuse daylight and artificial light.
Yellowing. The accelerated test described in last month's Art Resource post is also used for yellowing.
Dyes and Lakes. No paint pigments should be soluble in oil, water, or the volatile solvents. To test for insolubility, dust or blow a small amount on wet white blotting paper. Any solution will be immediately apparent. The same filter paper test is used with soluble dyestuffs to distinguish between single dyes and mixture of dyes.
Lighting. Color comparisons should be viewed in daylight; most of the artificial daylight lamps are unsatisfactory substitutes. Although an even north light (USA) is preferable, in the greater number of cases, direct bright sunlight is sometimes useful in examining blacks and other very dark colors.
Reference:
[1] The Artist's Handbook of Materials and Techniques, R. Mayer (ed. E. Smith) 4th Edition, Faber and Faber, London (1981).
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