Natural Pigments

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Mon, 30 Nov 2009 04:14:04 GMT

Acrylic dispersion grounds (we do not call this type of grond 'gesso,' because gesso is the Italian word for 'gypsum') are not absorbent, so charcoal will not adhere to this ground. Your only option is to use a fixative. Make sure the fixative contains a non-yellowing resin, such as ketone resins.

Re: Names for Iron Oxide Eath Pigments

carminnie — Mon, 30 Nov 2009 03:05:22 GMT

Yes am referring to acrylic gesso that you can suggest..in replacement for the usual enamel prime on canvas which usually turns yellow in time..i will be using charcoal on canvas...so is there any gesso that can hold the charcoal residue for a period of time...or something that will make it last on the canvas surface...and if ever, a fixative that does not turn the surface yellowish....

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Mon, 30 Nov 2009 02:51:12 GMT

You need to describe some more specifics as to the materials you are using. By gesso do you mean acrylic gesso? What do you mean by the charcoal drawing last?

Re: Names for Iron Oxide Eath Pigments

carminnie — Sun, 29 Nov 2009 23:17:46 GMT

HI GEORGE! I just wonder if you can give me some idea what would be the best Gesso preparation for canvas surface that would be a bit thinner in nature yet it will still enhance the canvas texture and would make a charcoal drawing lasts on it....thanks in advance for any information on this matter....

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Sun, 29 Nov 2009 23:07:45 GMT

Yes, I trust the web site and the company, because I am a director of the company, Natural Pigments.

Re: Names for Iron Oxide Eath Pigments

MonaYoussef — Sun, 29 Nov 2009 22:48:01 GMT

Thank you George, I have visited the website and might make order form there in Walleck's do not have it here!

Are you well familiar with this website? Do you trust it to make orders from there?

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Sat, 28 Nov 2009 21:27:32 GMT

A muller is a simple hand tool used to grind pigments to make your own paint. Here is an example you can see.

Re: Names for Iron Oxide Eath Pigments

MonaYoussef — Thu, 26 Nov 2009 16:46:17 GMT

Thank you George, will try it and let you know. When y say Muller, did you mean electronic blender?

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Wed, 25 Nov 2009 23:32:25 GMT

You can mix it with linseed oil, walnut oil or if you intend to paint in encaustics with different types of waxes.

Re: Names for Iron Oxide Eath Pigments

MonaYoussef — Wed, 25 Nov 2009 23:13:23 GMT

Thank you once agian Goerge but you still did not tell me what do you miix the pigments with?!

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Tue, 24 Nov 2009 21:56:19 GMT

The texture of rough and sandy occurs with some pigments, but most pigments will benefit by using a muller on a stone or glass slab so that you can grind the mixture to a smooth paste.

Re: Names for Iron Oxide Eath Pigments

MonaYoussef — Tue, 24 Nov 2009 20:34:02 GMT

Thank you Goerge,

You are right pigments do not get resolved for the fact that some colors remain very rough and sandy like. But what medium do you use to mix them with. I tried sulable wax, oil, safflower oil and others but they do not really give me the desirable result.

Mona

Re: Names for Iron Oxide Eath Pigments

George OHanlon — Tue, 24 Nov 2009 04:41:02 GMT

Pigment powders are not dissolved, but are mixed with paint vehicle. This forms a collodial suspension and not a solution, which is the result of dissolving one substance in another. To mix pigment powder with paint vehicle, does not require much. It can be done with a palette knife, but best results are obtained when using a muller on a flat, smooth slab of glass or stone.

Re: Names for Iron Oxide Eath Pigments

MonaYoussef — Tue, 24 Nov 2009 02:17:18 GMT

Thank you for the valuable information about earth iron oxide pigments. I find that each color in pigment format as different textures and can't be resolved or mixed same way. It would be great decussing such subject and what is the best way to desolve pigments powder?

Regards,

Mona

Calcite--Types, History and Use in Oil Painting

George OHanlon — Mon, 06 Apr 2009 02:59:26 GMT

Calcite--Natural Calcium Carbonate

Calcite is a naturally occurring calcium carbonate (CaO3) mineral chiefly found in rocks, such as chalk, limestone and marble. These rocks are the main sources for the pigment. Its whiteness, softness and fine-grained nature makes it an ideal white pigment, being both abundant and easily processed. Chalk is relatively transparent in most paint media and is therefore often used as an extender of other pigments and employed with animal glue as a ground for painting.

History of Calcite in Art
Calcium carbonate in various forms has a long history in art. It has been recognized, for example, in Greek and Roman art. Its use in art since that time has been both persistent and widespread. In northern Europe, from medieval times chalk was employed with animal glue for making the ground or preparation layer of paintings. Sometimes later lead white was mixed with the chalk to make it denser and whiter. Chalk was used with animal glue or with other aqueous binders as a white pigment.

Calcite has been used in oil painting, being added to colors, especially flake white, by such artists as Velázquez and Rembrandt. The transparency of chalk was desirable in some Dutch tonal landscapes of the seventeenth century.

Uses of Calcite in Paint
Calcium carbonate is commonly used in combination with other pigments in oil paint because of its low refractive index and hence poor hiding power. Linseed oil and chalk have long been used together, however, in the preparation of putty. The transparency of chalk in oil makes it ideal for adding bulk to oil colors or to affect the consistency (rheology) of paint.

Calcium carbonate is often used as an extender pigment to reduce the cost of paint. Its alternative names, such as chalk and whiting, are used in many formulations. An important use of calcium carbonate is in mixtures with titanium dioxide pigment to act as a spacer, keeping the titanium white particles spread apart, and ensuring better efficiency in scattering light and increasing opacity. Calcium carbonate is often used to vary the gloss of powder coating materials, depending on the particle size used.

Variations of Calcite and their Effects on Paint
Calcium carbonate derived from different mineral sources behave differently in paint. The material can be ground from limestone, a sedimentary rock formed in sea beads or alluvial deposits; or marble, which is limestone that has undergone heat and pressure below the earth's crust; or chalk, a light, low structure material normally associated with the sedimentary deposition of the shells of such minute marine organisms as foraminifera, coccoliths and rhabdoliths. The particle structure and chemical behavior of these variations of calcite all differ slightly.

The particle size and shape of calcite in regards to the behavior and performance of paint are important for several reasons. One is the viscosity of the paint, which is related to the volume occupied by the dispersed solids within the paint vehicle. In the case of particles that are not spherical, the “spherical equivalent” volume may be the maximum volume inscribed by the rotation of a particle. Because of this, a non-spherical particle may behave as if it occupies much more volume than it does.

Another consideration of the influence of particle size and shape on the behavior of paint is the surface area of the particle. The amount of paint binder required by a pigment to form a paste paint is called its oil absorption number. The greater the surface area of the particle, the more binder it demands to make into a paste or flowing paint. Synthetic (precipitated) calcium carbonate that consists of 0.05 micron needle-shaped particles has more surface area than the particles of ground limestone of the same size, which have simple structures resembling rhomboidal crystals. Because of the complex surface of the precipitated calcium carbonate, it will tend to scatter more light and consequently appear more opaque than the ground limestone particles. However, it is likely that this precipitated calcium carbonate will consume considerably more binder than the ground limestone.

Selecting the right type of calcite, taking into consideration particle size and shape, brightness, chemical constituents, and surface treatment are important factors when it comes to making paint or oil painting mediums.

The Palette of Michael Sweerts

George OHanlon — Tue, 17 Mar 2009 19:04:16 GMT

It is no coincidence that the palette in the self-portrait by Michael Sweerts is practically identical to the palette described in detail by Roger de Piles in his 1684 book, Les Premiers Elémens de Peinture Pratique. Sweerts was a contemporary of de Piles, and it appears that his palette was laid out in the manner practiced throughout western Europe in the 17th century.

The pigments on the palette held by Sweerts in his self-portrait were analysed in detail in 1954 by Richard Buck and R. J. Gettens, and can be identified as: 1) vermilion, 2) red lake (likely madder lake), 3) white lead, 4) yellow ochre, 5) red ochre or Venetian red, 6) terra verte, 7) a warm brown lake (stil de grain or brown pink?), 8) a cool brown pigment (unidentified, but likely a brown iron oxide earth pigment), 9) raw sienna, 10) Vandyke brown (or carbon black), and 11) an unidentified pigment that was lost.

Although we do not see the same arrangement of columns of shadow and half-tints prescribed by de Piles in his book, we do see mixes of vermilion and lead white like those written by de Piles.

Sweerts was baptized in Brussels on 29 September 1618. By the mid 1640s, he was living in Rome, where he remained until at least 1652. Back in Brussels, Sweerts opened an academy for life drawing in 1656, and became a member of the St. Luke's Guild in 1659. During a brief stay in Amsterdam in about 1660-61, he became a lay brother in the Lazarist Société des Missions Étrangères, and joined their mission to the Orient in late 1661. He was dismissed from the mission in 1662 because of his mental instability and ungoverned zeal, and died at the Portugese Jesuit colony at Goa in 1664.

In addition to portraits, Sweerts painted genre scenes and history paintings that combine stark chiaroscuro and blunt realism with a serene, almost classical simplicity.

Detail about the self-portrait: Michiel Sweerts (Flemish, Brussels 1618 - 1664 Goa [India]), Self-Portrait, ca. 1656, Oil on canvas, 37 1/4 x 28 7/8 in. (94.5 x 73.4 cm), Allen Memorial Art Museum, Oberlin College, Oberlin, Ohio.

Names for Iron Oxide Eath Pigments

George OHanlon — Tue, 17 Mar 2009 18:17:57 GMT

Natural iron oxide pigments or iron oxide earth pigments, collectively referred to as iron oxides, comprise both oxides and oxide hydroxides of iron. Hematite (α-Fe2O3) is the most common iron oxide in red earth pigments and the iron oxide hydroxide goethite (α-FeOOH) is the most frequently found iron compound in yellow earth pigments. Umbers are brown earth pigments containing both oxides of iron and manganese.

Names for natural iron oxide pigments are complex and inconsistent. Yellow pigments based on iron oxide hydroxides are referred to by many different names, including goethite, limonite, raw sienna, Mars yellow, yellow earth, yellow ocher, yellow iron oxide, yellow hydrated oxide and iron hydroxide pigment. Similarly, references to natural red pigments, based on anhydrous iron oxide, are referred to with such names as hematite, red earth, red ocher, burnt sienna, Mars red and red iron oxide.

The problem is compounded further when manufacturers label synthetic iron oxide pigments with names typically associated only with earth pigments, such as a artificial yellow iron oxide labeled as yellow ochre.

The general term iron oxide pigment is an appropriate name when referring to both natural and synthetic materials that may contain mixtures of iron oxides and iron oxide hydroxides. The names earth and ocher are suitable when it is clear that the pigment comes from a natural source. Earth is a more general term, since ocher refers to a specific type of iron oxide deposit containing kaolinite (clay) and quartz. Hematite is used to differentiate the crushing of mineral hematite, which contains iron oxide in a finely divided form and is usually associated with clay or other minerals. Umber refers to a chemically distinct class of brown earth pigment containing manganese and iron.

The Colour Index (1982, 1:16-17, 120-122, 64-65) lists natural red iron oxide pigments as CI Pigment Red 102 (nos. 77015, 77491 and 77538). Synthetic red iron oxide pigments are listed as CI Pigment Red 101 (nos. 77015, 77491 and 77538). The natural and synthetic yellow iron oxide pigments are listed as CI Pigment Yellow 43 and 42 (no. 77492), respectively. CI Pigment Brown 6 and 7 (nos. 77491, 77492 and 77499) designate the synthetic and natural brown iron oxide pigments, including umbers.

Generally, we can summarize the various iron oxide pigment names and their Colour Index designations as follows:

Colour Index
Pigment Names

Yellow Earth Pigments
Pigment Yellow 43
Limonite, goethite, jarosite, yellow ocher, yellow earth, yellow iron oxide, raw sienna

Red Earth Pigments
Pigment Red 102
Hematite, red earth, red ocher, burnt sienna, red iron oxide

Brown Earth Pigments
Pigment Brown 7
Pyrolusite, umber, burnt umber

To determine whether a pigment is from a natural source, such as an earth iron oxide pigment, look for the Colour Index designation, such as Pigment Yellow 43 (PY43), Pigment Red 102 (PR102) or Pigment Brown 7 (PBr7).

Colors from the Earth: Violet Hematite

George OHanlon — Tue, 17 Mar 2009 18:13:17 GMT

Colors from the Earth: Violet Hematite

Rublev Colours Violet Hematite is a deep reddish purple hue that tints toward subtle violets when mixed with white.

By George O'Hanlon

Rublev Colours Violet Hematite is a deep reddish purple hue that tints toward subtle violets when mixed with white. It is useful in flesh tints, shadows and its purple bias makes good grays. Rublev Colours Violet Hematite is formulated using pure natural ground hematite (Colour Index Name Pigment Red 102) that is absolutely permanent and very opaque. This beautiful earthy red violet is cooler than other red iron oxide earths, such as Venetian red or Sartorius red.

Every pigment is capable of yielding two distinct hues according to whether it is painted transparently or solidly mixed with white. The effect of using Violet Hematite painted thinly transparent and in solid color extends the range of hues accessible with it. Try rubbing a little Violet Hematite on a white surface, mixed with oil or a painting medium, sufficiently thinned to show the white surface through it. You get a purple lake hue. Now take the same color and mix a little white paint with it and paint it solidly across the thin paint. It is quite a different color. The shift is more dramatic in Violet Hematite than in many other colors. The explanation for these color differences was observed by Harold Speed (1987), ‘All colors are made warmer when painted over light grounds transparently, and all colors are made colder when mixed with white.’

Rublev Colours Violet Hematite is ground in linseed oil without the use of any stearates or other additives that affect the behavior of the pigment in oil. The pale linseed oil used to make this color is well aged and refined to provide higher levels of reactivity and oxidation than raw oil. The consistency is a smooth, thick, rich color that brushes ‘long’[1] yet holds its shape remarkably well. When the color is brushed out it readily flows under the brush, but when the brush is lifted it remains in place, staying put.

About the Pigment

Group	Iron oxides and hydroxides
Subgroup	Hematite, Iron(III) oxide
Synonyms	Caput mortuum, Mineral purple, Purple ocher, Mars violet
Specific Gravity	5 (water=1)
Oil Absorption	15 g / 100 g oil

Hematite is the mineral form of iron(III) oxide and the principal colorant in red, brown and purple iron oxide-based pigments, both natural and synthetic. Hematite is a major source of iron oxide earth pigments and a component of ocher, umber and sienna colors. The mineral is found in many places throughout the earth, a primary source of the pigment from soft, red earthy masses of hematite called ‘paint ore.’

The iron content (as Fe₂O₃) of the pigment used in Rublev Colours Violet Hematite is 98 percent. It is a heavy mineral, having a specific gravity of 5 (water, for example, has a specific gravity of 1). With a mean particle size of 1.8 microns and high density, it has very low oil absorption (15 grams of oil for 100 grams of pigment), which means that it requires very little oil to make a medium stiff paste paint, making it a very lean color.

Hematite mineral specimen from 'paint ore'

What is unusual about the pigment used in Rublev Colours Violet Hematite is the micaceous structure of its particles. Hematite is most often found in crystalline form, but more rarely as micaceous hematite (also called specular hematite or specularite) consisting of very thin leaves of iron ore with the metallic luster of polished iron. These small, hexagonal plates produce a glistening effect, giving the paint a metallic sheen (Schmelzer, 1976). This effect, known as ‘bronzing,’ gives Rublev Colours Violet Hematite a metallic cast that appears on the surface of pure and densely applied paint.

The color of hematite, which can range from yellowish red to cold tones of purplish red, depends on the particle size of the pigment. Helwig (1998) identified violet iron oxide colors as consisting of coarser particles of hematite than the red shades. Particles of size 0.1 to 0.2 microns appear bright red whereas a blue-red to purple color is observed with 1 to 5 micron grain size. In their paper, Oliveira et al. (2002) used Raman spectroscopy to characterize modern purple iron oxide pigments. They too noted the variation in color from these samples as related to the particle size of the pigment. Interestingly, this variation of color from red to purple can be observed in Rublev Colours Violet Hematite during grinding and when brushing the color out thinly.

History of the Color

The name hematite is derived from Greek word haima, referring to blood, undoubtedly due to its red color. The use of this mineral as a pigment is one of the earliest in humankind history. Theophrastus’ On Stones (c. 315 B.C.E.) is the earliest known reference to what is thought to be hematite; his name for the material, which translates bloodstone, was apparently based on its blood red appearance. Some four hundred years later, Pliny the Elder (c. 77 C.E, Book xxxvii) used hæmatite, the Latin equivalent, in his widely cited Historia Naturalis.

Recent analyses of purple iron oxide colors described in several papers (Bikiaris et al., 1999; Daniila et al., 2002; Oliveira et al., 2002) show that hematite rich pigments were used in Roman, Byzantine and post-Byzantine art.

James Ward (1915) and Arthur Pillans Laurie (1949) argue that the sinopia and cinabrese described by Cennino Cennini in his 15th century painting treatise must have been varieties of hematite, which Ward describes as ‘similar, if not the same substance as that which is now known as Indian or Persian red.’ He goes on to describe the qualities of the hematite variety known as ‘Indian red,’ a purplish red iron oxide: “the quality and properties of the finest and purest Indian red, and its beautiful tints when mixed with lime-white, which have the appearance of delicate lake tints, are exactly such as he describes when sinopia and cinabrese are mixed with bianco sangiovanni (lime-white).”

Several sixteenth century authors cited by Mary Merrifield in The Art of Fresco Painting (1846) describe a pigment known variously as lapis amatita (Baldinucci), lapis amatito (Borghini), amatita, matita rossa (Palomino), and albin (Pacheco), which she convincingly argues refers to hematite.

Chamber’s Cyclopedia (1738) states that a kind of purple hematite called ‘Indian red’ was ‘brought from the island of Ormus in the Persian Gulf.’ However, in The Handmaid to the Arts‎, Robert Dossie (1764) states that this color was prepared from caput mortuum, an artificially prepared pigment made by the aqueous precipitation of iron salts with alkalis, which are then roasted to produce dark purple shades of iron(III) oxides. George Field in Chromatography (1835) describes purple ocher as a native ocher from the Forest of Dean, Gloucestershire, England, though in the 1841 edition of his book he notes that it can be prepared artificially by calcining natural red ocher and ‘has been employed under the denomination of Violet de Mars.’

New from Natural Pigments

Although Violet Mars oil colors based on synthetic iron oxide can be found among the colors made by other artists' paint manufacturers, Natural Pigments introduces the only natural purple iron oxide oil color with micaceous particles in Rublev Colours Violet Hematite.

For More Information or to Order

Rublev Colours Violet Hematite Artists' Oil

See more Rublev Colours Artists' Oils

Notes

1. Long refers to the consistency of paint that displays tall peaks when a palette knife is pressed to its surface and lifted. Long paint is also described as being a "ropy" and refers to a stringy quality, like that of honey. Paint that behaves in this way is said to have long rheology. Short rheology refers to paint that exhibits a more buttery consistency, typical of most commercial oil paint. Rheology is the study of how substances flow, such as liquids and soft solids that flow rather than deform elastically.

References

Bikiaris et al. (1999) Bikiaris, D.; Daniila, Sr.; Sotiropoulou, S.; Katsimbiri, O.; Pavlidou, E.; Moutsatsou, A.P.; Chryssoulakis, Y. ‘Ochre-differentiation through micro-Raman and micro-FTR spectroscopies: application on wall paintings at Meteora and Mount Athos, Greece,’ Spectrochemica Acta, Part A 56 (1999) 3–18.

Chambers (1738) Chambers, E. Cyclopaedia: An Universal dictionary of Arts and Sciences. Midwinter, London (1738).

Daniila et al. (2002) Daniila, Sr.; Bikiaris, D.; Burgio, L.; Gavala, P.; Clark, R.J.H.; Chryssoulakis, Y. ‘An extensive non-destructive and micro-spectroscopic study of two post-Byzantine overpainted icons of the 16th Century,’ Journal of Raman Spectroscopy 33 (2002) 807–814.

Dossie (1764) Dossie, Robert. Handmaid to the Arts, 2nd ed. London, 1764.

Field (1835) Field, George. Chromatography: or a Treatise on Colours and Pigments, and of their Powers in Painting. Charles Tilt, London, 1835.

Field (1841) Field, George. Chromatography: or a Treatise on Colours and Pigments, and of their Powers in Painting. Tilt and Bogue, London, 1841.

Helwig (1998) Helwig, Kate. ‘Mars colours: preparation methods and chemical composition,’ Painting Techniques History, Materials and Studio Practice, Summaries of Posters at the IIC Dublin Congress, 7-11 September 1998 IIC, London, 1998.

Laurie (1949) Laurie, Arthur Pillans. The Technique of the Great Painters. Carroll and Nicholson, 1949. 63.

Merrifield (1846) Merrifield, Mary P. The Art of Fresco Painting: As Practiced by the Old Italian and Spanish Masters. Charles Gilpin and Arthur Wallis, London, 1846.

Oliveira et al. (2002) de Oliveira, L.F.C.; Edwards, H.G.M.; Frost, R.L.; Kloprogge, T.; Middleton, P.S. ‘Caput mortuum: spectroscopic and structural studies of an ancient pigment,’ The Analyst 127 (2002) 536–541.

Sikong et al.(2001) Sikong, Lek; Pongramun, Thitipun; Phunmuang, Natsima. ‘Fine grinding of hematite for making pigment,’ Songklanakarin Journal of Science and Technology, Vol. 23 Issue 3 (2001). 391-397.

Schmelzer (1976) Schmelzer, H. XIII Congress FATIPEC (Fédération d'Associations de Techniciens des Industries des Peintures, Vernis, Emaux et Encres d'Imprimerie de l'Europe Continentale), Cannes, Juan les Pins 1976, Congress book, 573–574.

Speed (1987) Speed, Harold. Oil Painting Techniques and Materials. Dover Publications, New York, 1987. 118.

Ward (1915) Ward, James. History and Methods of Ancient and Modern Painting. Dutton, 1914. 184–185.

Gel Oil Painting Medium

George OHanlon — Tue, 17 Mar 2009 17:28:56 GMT

Rublev Colours® Oleogel

Oleogel is a thixotropic painting medium made with linseed oil and pyrogenic silica. Oleogel is a clear pale amber gel that adds transparency and thixotropic body to oil, resin-oil or alkyd paint. Add directly to your paint to give it transparency without thinning its consistency. Add pigments or extenders to thicken it for creating impasto effects that do not sink in.

Oleogel does not contain driers, so it is safe to use in oil painting without worry of cracking. When mixed with paint, you may find that Oleogel slows the drying time. However, most artists who have used Oleogel find that it does not extend the drying time of oil colors.

Oleogel is available in 8 ounce (236.6 ml) tins.

Oleogel adds transparency to whites without losing the body of the paint
Oleogel in the center, Flake White on the left and a mixture of Oleogel and Flake White on the right. The Flake White is stiff, plastic and short, but when mixed with Oleogel the mixture is semi-transparent, soft, yet sculptural.

Oleogel increases transparency without flowout and leveling
Rublev Colours French Raw Sienna at left and a mixture of Oleogel and Raw Sienna on the right. Below each is a brush out of the above examples. Rublev Colours French Raw Sienna is long, yet holds strokes well. When Oleogel is added to Raw Sienna it increases transparency without causing the flowout and leveling of brushstrokes.

Directions

Mix directly into your paint right on the palette.

To make your own paint with Oleogel, add directly to pigment powder until a stiff paste is obtained (almost the consistency of putty). Grind the paste with a muller on a flat surface before storing in collapsible tube. Some of its thixotropic property will be temporarily lost when grinding Oleogel with a muller, but should be restored when allowed to stand.

Questions and Answers

What is a thixotropic gel?

Thixotropy is the property of some fluids to change viscosity as they are agitated. The longer the fluid is agitated, the lower its viscosity. A gel is mostly liquid in composition, but behaves more like a solid. When a thixotropic gel is agitated, such as manipulated with a palette knife or brush, it begins to flow, but when the agitation is stopped it regains its former viscosity and stiffens.

What are the working properties of Oleogel?

Oleogel increases the transparency of colors without making paint more fluid, such as when adding drying oil to increase the transparency of a color. This is an advantage when you want a transparent layer of color without making the paint runny. The pyrogenic silica in Oleogel adds a little drag while brushing and its translucency creates wonderful possibilities for layered painting techniques.

Can I use Oleogel to make opaque impastos?

Oleogel increases the transparency of colors. By adding a small amount of Oleogel to your paint, you can maintain the body of the paint while only slightly increasing its transparency. Oleogel is a soft gel so that as you add more to your paint the softer and more transparent it will become. For heavier impastos or textures, we recommend adding calcite (calcium carbonate) and bodied linseed oil to Oleogel in combination with your oil colors.

I use a wax medium with my oil paint. Can Rublev Colours Oleogel be mixed with this medium?

Oleogel is compatible with wax pastes and resinous mediums. We do not recommend heating Oleogel to mix it with wax, but rather add the wax as a soft paste directly to Oleogel or melt the wax in linseed oil before adding it to Oleogel.

Can I add driers to Oleogel to hasten drying?

Oleogel does not contain driers, so you can add driers to it to speed its drying time. You will most likely find that driers are not needed. However, if you find driers necessary, add them as you would normally use with oil paint.

Order Oleogel Now

Oleogel (8 oz can)
$16.50

Lead Oil Grounds

George OHanlon — Tue, 17 Mar 2009 17:05:56 GMT

Rublev Colours^® Lead Oil Ground

Rublev Colours Lead Oil Ground is a blend of white pigments and linseed oil for a semi-absorbent ground ideal for oil painting. It dries within two days to one week, depending upon local conditions, such as humidity, light and temperature. You can usually begin painting within two weeks if allowed to dry in warm, well-lit and dry environment.

Rublev Colours Lead Oil Ground contains ground calcite, lead white and titanium white in just the right proportions to make a paint film that remains flexible and tough with some absorbency. The blend of linseed oil provides penetration into the support to ensure good adhesion yet maintain sufficient holdout to form a good foundation for paint layers. It provides the good leveling properties, so brush and knife marks are minimized.

Rublev Colours Lead Oil Ground has a high concentration of pigments so only two coats are usually necessary, but more coats create smoother surfaces. Apply directly onto panels without sizing or on canvas sized with PVA or rabbit skin glue. Rublev Colours Lead Oil Ground is an excellent foundation for oil and alkyd paints.

The important characteristics that grounds should have are (1) adhesion, (2) flexibility, (3) penetration control, (4) a type of surface to which upper layers can adhere well, (5) blister and crack resistance, and (6) good application properties. Careful selection of ingredients in an oil ground is essential to impart these qualities to the ground. Ground natural calcite (calcium carbonate) in combination with lead white (basic lead carbonate) and a maximum chalk-resistant grade of rutile titanium dioxide have proven to be an excellent choice of pigments in such oil grounds.

Three Pigments

We make Rublev Colours Lead Oil Ground using all three white pigments; calcite, lead white and titanium white in just the right proportions to make a film that remains flexible, tough and has some degree of absorbency.

The dry ground calcite we use in Rublev Colours Lead Oil Ground has a closely controlled particle size distribution. This grade of calcite is designed to provide the lowest possible oil absorption. It offers the desired penetration control with maximum chalk resistance. Calcite aids in forming the type of surface on grounds to which upper layers will adhere easily.

Lead white, and to a lesser degree, ground calcite, have low water absorption properties and hence develop better blister and crack resistance. Furthermore, lead white contributes to more film flexibility.

The presence of titanium white increases the opacity of this ground and provides a brilliant white surface. We have selected a grade of titanium white that exhibits good hiding and excellent dispersion properties.

Does Not Contain Zinc

Many manufacturers use zinc white to get a brighter white in their white grounds and paint. Zinc oxide is not recommended in oil grounds, since it tends to cause blistering and cracking in oil paint and grounds. We have not used any zinc in this product.

Pure Linseed Oil

After many trials, we have carefully chosen a specific blend of refined and raw linseed oil with heat-bodied linseed oil such that there is a limited penetration of the oil into the canvas or panel to assure good adhesion to this substrate and yet maintain sufficient holdout to establish a good foundation for the upper layers. This blend of linseed oil also provides the best possible leveling properties, so brush and knife marks are minimized.

Rublev Colours Lead Oil Ground is ready to apply to canvas or panel without thinning. It is available in cans:
8 fluid oz. (236.6 ml)
Pint 16 fl. oz. (473.2 ml)
Quart 32 fl oz. (0.95 L)

Questions and Answers

Can Rublev Colours Lead Oil Ground be thinned with turpentine for application?

Rublev Colours Lead Oil Ground can be thinned with turpentine or mineral spirits, however, do not over thin. It is the consistency of heavy cream, so it can be used straight from the can and applied with a brush or knife. This consistency is best suited to penetrate the weft and warp of canvas or the grain of wood panels.

If I applied a single coat of Rublev Colours Lead Oil Ground on sized canvas would that be sufficient as a ground for oil painting?

We recommend at least two thin coats over a sized canvas or panel, as opposed to a single application of a thick coat of oil ground. This ensures even coverage of the ground and speeds drying. Oil paint dries through autoxidation by exposure to air. The drying begins at the surface and gradually penetrates through the layer of oil. To completely harden, oil paint must dry through the entire layer. If the layer is thin, it has more surface area exposed to the air per unit weight of vehicle and hence this process proceeds more rapidly.

Wait until the first coat is dry to the touch before applying the next coat of Lead Oil Ground.

After applying, how long do I have to wait before I can paint over it?

That depends on many factors, such as the relative humidity, temperature, light exposure, application thickness, substrate absorbency, etc. It is difficult to give a recommendation that covers all applications, but we recommend waiting at least two weeks before painting over it and more time may be required.

Is Rublev Colours Lead Oil Ground flexible enough for large stretched canvases or is it only suitable for panels or panel mounted canvases?

It forms a flexible coating for stretched canvases even when applied in multiple layers.

What role does the calcite play?

The medium dry ground calcite in Rublev Colours Lead Oil Ground has a closely controlled particle size distribution. This grade of calcite provide the lowest possible oil absorption, reducing the amount of vehicle necessary to make a flowing ground and allowing it to contain more pigment (pigment volume concentration or PVC). The high PVC (above 40%) of Rublev Colours Lead Oil Ground makes a stronger film and with calcite gives the grounds the desired penetration control with maximum chalk resistance. Calcite aids in forming the type of surface to which upper layers adhere easily -- it provides the "tooth" necessary for good adhesion.

What type of bodied oil is used as an ingredient of Rublev Colours Lead Oil Ground?

Rublev Colours Lead Oil Ground contains bodied linseed oil that is heat treated in a vacuum until it reaches the consistency of honey -- Z₆ viscosity on the Holt-Gardner scale. Bodied oil gives Rublev Colours Lead Oil Ground good flowout and leveling properties, minimizing the need to scrape or sand smooth the ground to eliminate brush or knife marks.

Can I add driers to Rublev Colours Lead Oil Ground to reduce the drying time?

Rublev Lead Oil Ground already contains a blend of lead, cobalt and calcium driers, accurately added to provide the best drying characteristics. Adding more driers to the oil ground will not reduce the drying time significantly and possibly deter drying.

How to Use

Stir the contents of the can before using. Some settling of the pigments will occur and is normal.

Apply the ground straight from the can with a palette knife, plastic trowel or brush to a properly sized canvas or panel. If it is too thick to spread easily in a thin layer, thin with a small amount of mineral spirits or spirits of gum turpentine.

Use a brush to smooth out any knife or lap marks to obtain an even, consistent coating.

We do not recommend sanding any lead oil ground, because this will create dust containing lead. If you find it absolutely necessary to sand the ground, we recommend wet sanding the ground once it has dried thoroughly.

Allow the ground to dry, usually overnight or in a day or two, depending upon local conditions. Apply a second coat, repeating the procedure above. More coats can be applied, but two thin coats are recommended.

You can begin painting when the ground has dried thoroughly, usually about two weeks in warm environments and longer in cool, damp environments.

You can dilute Rublev Colours Lead Oil Ground with mineral spirits or spirits of gum turpentine for thinner coats that may be easier to spread over pre-primed canvas or boards with acrylic-dispersion grounds.

WARNING: CONTAINS LEAD. Harmful if swallowed. When using do not eat, drink or smoke. Avoid ingestion and skin contact. Wear gloves and protective clothing to avoid exposure to broken skin. If swallowed, do not induce vomiting. Call a physician immediately. KEEP OUT OF REACH OF CHILDREN.

Natural Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Re: Names for Iron Oxide Eath Pigments

Calcite--Types, History and Use in Oil Painting

Calcite--Natural Calcium Carbonate

The Palette of Michael Sweerts

Names for Iron Oxide Eath Pigments

Colors from the Earth: Violet Hematite

Colors from the Earth: Violet Hematite

Rublev Colours Violet Hematite is a deep reddish purple hue that tints toward subtle violets when mixed with white.

About the Pigment

History of the Color

New from Natural Pigments

For More Information or to Order

Notes

References

Gel Oil Painting Medium

Rublev Colours® Oleogel

Directions

Questions and Answers

Lead Oil Grounds

Rublev Colours® Lead Oil Ground

Three Pigments

Does Not Contain Zinc

Pure Linseed Oil

Questions and Answers

How to Use

Rublev Colours^® Lead Oil Ground