Practice of Oil Painting - Priming the Fabric

If you are making a trace of a conceptual art work, you may consider the object you make an homage to process.  (Happy 100th to Dada)

If you intend to make an oil painting, the BACK of painting should not look like this one. (Image 1)        


Allowing oil binder to saturate the fabric compromises quality by destabilizing the pigment-to-oil ratio.  When too much binder leaches out of the paint, pigment can dust off the surface until the painting looks more stained than painted.  Mars Black, in particular, is a lean paint which means it has less binder - a high pigment-to-oil ratio.  (Images 2 & 3 -  under bound painting.  Image 4 - thick well bound painting.)  

Linseed oil is the traditional binder for artists’ colors because it is easily available and dries to a firm film within a reasonable time frame (5 - 7 days).  When made into paint, linseed oil surrounds particles of pigments. Colored pigments cohere with potential to flow.  When the oil in paint sinks into fabric, the pigment is under bound on the surface. The resulting surface is matte and can look crumbly.  

When artists spread out a paint layer and expose it to oxygen, the linseed oil binder begins to form into layers.  Initially, layers dry by absorbing oxygen and expanding. When paint films release oxygen in the next phase of drying, the paint film shrinks. Depending on thickness of the paint layers and additives, the interior layers may take years to dry completely. All the while through all the years drying paint on an unprimed canvas continues to pull fabric threads apart as it shrink. When primed, most of the stress on an aging traditional oil painting is on the size/ground layers not the fabric.  

While the mechanics of old oil paintings are fascinating, the issue for painters today is: how long do you expect your painting to last?  how matte do you want your paintings to be?  

If you paint on unprimed fabric, your paintings will be matte unless you add resin and varnish.

If you paint on acrylic gesso, the question is how much.  You really need to apply three to five solid coats of top quality gesso. Takes a lot of gesso to do the work of two thin coats of oil ground.  Using oil ground is a hassle in my opinion because of the size.  The size isolates the oil ground from the fabric.  

Priming the surface is probably the only part of contemporary painting that reveals to us what painters of the past experienced.  Most of their painting layers required isolating varnishes.  Most ingredients were reactive.  Pigments were poisonous.  Lead had to be isolated from Vermillion so it didn’t turn black.  Oil binders were contaminated with weed seed and dried very slowly.  Animal glues had to be prepared from skins!  Nothing was available at the art supply store.  

If you want to use oil ground and stretch your own canvases, apply PVA size before you stretch because PVA slackens fabric.  

If you paint on panel, do what you want.  

The Practice of Painting - Fabric Supports

As early as the 10th century, Venetian painters were using fabric supports for their church banners. Traditionally, icons were painted on wood panel and often ceremoniously carried in procession from one church to another on the feast of St. Mark, for example.  But parading around waterways and through narrow streets carrying tall poles supporting wood panels must have been too great a penance.  Venetians painters had to find another way.  After replacing the paintings on wood panel with paintings on canvas, their banners could be carried longer and lifted higher without breaking any backs.  

"Canvas" is derived from the Arabic word for cloth. Hemp, the oldest and cheapest fiber for cloth, might have been first choice for the early experimenters despite its coarse fiber and the open weave of most hemp (burlap) fabric.  While more durable, hemp fibers absorb more water than linen. Hemp fibers are not suitable for dyeing. That fact - hemp fibers are not suitable for dyeing - determined hemp’s place in industry and agriculture.

Human beings want to be around color.  We have been making paints to illustrate limestone walls, tattoo skin and dye fabrics for at least 100,000 years.  Since time before the Egyptians, humans have cultivated flax and cotton, crops that produce fibers suitable for dyeing.  

Fibers from both hemp and flax plants are harvested from stems.  Flax yields both linen fibers and linseed oil and is among the earliest cultivated crops about 10,000 BCE.  Linen threads are long tough fibers.  Cotton, a short, softer fiber harvested from the plants’ flowers, was cultivated in the Indus Valley about 7000 BCE.  Linen, cotton and hemp fibers, threads and cloth have been consistently traded by every civilization through history.  

From 5th to 18th centuries, Venice was the trading hub bridging Europe, Africa and Asia. The crusades launched form Venice. It is well documented that in the maritime industry linen sail cloth with tight weave and pale color was widely used, especially for smaller sails.  For artists, I doubt there was much discussion about the choice between hemp and linen as a support for paintings.  Linen’s strength and pale color would trump price.  In procession, colorful linen banners must have flowed like sails lifting the prayers and songs of the faithful into the wind.  

Regardless of fiber, the most common weaving technique to make fabric is warp/weft:

Choosing the Right Solvent

Just when or maybe because oil painting has lost its cache as “primary media,”  young painters are intrigued by the myths and tall tales of bygone days. Simultaneously they seem under educated about studio practices before the Industrial Revolution.  

For decades, artists have not been trained how to use oil painting materials and techniques in 80% of America’s art schools and colleges. I remember when the EPA issued citations and fines to art schools for mishandling of toxic waste like turpentine about 30 years ago. The Rhode Island School of Design improved their oil painting program when most schools simply banned the use of solvent.  

Oils, acrylics, pastels, watercolor and other art media are made from the same basic pigments.  Managing artists’ colors using multiple media is not as difficult as managing binders.  Previously artists did not have so many ways to bind pigments.  Until the invention of European style oil painting about the 14th century, master painters could choose tempera, fresco or mosaic.  

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What is revolutionary about adding linseed oil as a binder is transparency added to the painting process.  Historically, raw linseed oil had been prepared for industrial varnishes by boiling it with various natural resins like copal and mastic.  Refined linseed oil was used for medicine and in cooking. The quality used in medicine was probably more aromatic but similar to the cold pressed linseed oil you can buy from health food stores today, probably just as expensive. 

It would not take long for the experimental painters of the era to see film failure if their paint layers were too fat. Adding the correct measure of solvent increases cohesion because solvent defats the oil just so a layer of color can “bite” into the layer beneath. As history has demonstrated these materials when combined correctly make strong paint films. And the process captures light deep inside multiple paint layers.  As the light struggles to be released, the painting surfaces glow.    

Since the 14th century mixtures of solvent/oil were common mediums. The oil to solvent ratio can be adjusted between layers (fat over lean). If there are any secret recipes from the Old Masters, these must be the ratios between oil/solvent + pigments used to create unusual surface effects!  Very tricky to find the balance.  

Unlike contemporary media, oil painting materials are very simple, very raw materials.  Because colorants + oils + solvent can be combined any way at the will of the artist, mastering this media is technical.  If your plan is to go the art store and buy a bunch of stuff and make an oil painting, rethink your plan. It would be so much easier to buy acrylics painting materials.  Painting in acrylics is true 20th century media.  Art materials manufacturers, especially Golden Artist Colors, have scientific research and technical data to satisfy any painter. 

If you insist on buying a bunch of stuff and painting in oils, start by choosing the right solvent.  

To thin oil binders, the solvent has to be hot enough to reduce the viscosity of oil to make, for example, a glaze layer.  Gamsol and Turpenoid are two brands of ODORLESS MINERAL SPIRITS (OMS) commonly available to painters. Gamsol is just hot enough to dissolve vegetable oils like linseed oil, poppy and safflower oils. OMS is not enough strong to dissolve natural resins like damar and copal.  

To know the solvent power, look at the Permissible Exposure Level (PEL), the higher the PEL, the weaker the solvent. Turpentine is “hot” - PEL of 100.  OMS is less strong - PEL of 300.

Despite the historical, mystical allure of “traditional” oil painting and the siren’s aroma of turpentine, OMS is the only solvent that should be used in oil painting today  

Had painters of the past had access to safer solvents, they would have used them. Throughout art history, innovations were embraced by artists like water-based media has been embraced by artists today. For those intrigued by oil painting, get use to working with OMS rather than a stronger solvent. At Gamblin Artists Colors we use to say:  painters can respect the traditions of the past while facing the future, which is in studios with no or low exposure to solvent.  


Generational Shift

Reducing reality to predictable materials and reliable colors was a strategy to cope for Alberto Burri plus his art materials were inexpensive and easy to get. Minimalists or whatever, artists have always selected various industrial materials to make their art work especially during times like The Great Recession when paintings don't sell steadily.   

Some NY school painters relied on industrial paints and surfaces. Except for black and white, the paintings & coatings industry knows you want to re-paint your walls every five years so the colors intentionally shift and fade. Many acrylic paintings from the 60s didn't make it, many were experimental like the times.  However, art materials manufacturers started producing decent quality water-based acrylics by the end of the 60s and excellent acrylic art paints by the 80s.  

An early paint, the Bocour brand “Magna” was formulated by Sam Golden, a sort of middle ground between the alkyd resins paints of Jackson Pollock’s drip paintings and the color waves painted by Morris Louis.  Morris Louis painted/poured very fluid paints on to large surfaces. Trying to make large paintings using fluid oil paints really exposes the painter to an excessive amount of solvent. Morris Louis was an early adapter of water-based paints.

Artists have been perfecting the techniques for applying acrylic paints for about 65 year but until now the art market has not favored acrylic paintings. Now paintings  are selling again. The new buyers, collectors and patrons do not seem to care much about the art media of the objects they buy.  

Because art buyers don’t care and the schools prefer to teach water-based painting systems, the art market is seeing more than just a generational shift.  Until 2005, oil paintings were considered the most valuable.  The primacy of oil painting - a tradition more than 500 years old, may be a casualty of The Great Recession. 

For painters using acrylic media, the challenge is establishing value - relative  lightness and darkness. That was ultimately Goethe’s quarrel with Newton’s OPTICKS.  Humans see more contours and shadows than we do bright colors on flat surfaces.  Also do not wash acrylic paints down the drain.  Acrylic paints contain the same pigments as oil paints. Pigments do not belong in local watersheds.  Just because a paint media is water-based does not mean it is safer for the environment.  

Dazzled by Limestone Cave Paintings




 I am bedazzled by the sheer innovation of painting on limestone, the chemical composition of which includes calcium carbonate.  I am amazed because we are still painting on gesso and using calcium carbonate as a key ingredient in artists’ paints.  Imagine for 100,000 years painters have had the technology to make paint but when did we start making paintings on limestone walls? 

Humans who fished did have an early need for oil varnish.  Before ancient boats could float, the wood had to be coated with oil/varnish mixture containing if not linseed oil then a progenitor.  They needed an oil varnish that hardened into a waterproof film.  When were colorants added to the oil varnish? Probably when I wanted to find my boat.

By adding colored pigments - carbon black, calcium carbonate white, yellow ochre, iron oxides and hematite to varnish, human had another way to differentiated objects.  Being able to select my boat from many boats seems like a good reason to add color.  The leap from using color to differentiate my boat to using color for storytelling is a long one.  Did original painters have a painting tradition before they found the caves or did they find the caves when they had something to say?

A breakthrough must have been finding bright limestone walls of caves undisturbed by animals or inhabited by humans, secure places to leave their paintings as messages, for rituals or ?  

Perhaps painters added a white wash then applied colors with some fluidity into dampened limestone walls in a manner similar to techniques used to make frescos by Egyptians, Romans, Greeks, Europeans among others.   As it dries, quicklime reacts with carbon dioxide in the air and convert to calcium carbonate.  Its components, calcite and aragonite form a crystalline structure across the painted surface, sealing in line and color.  

There are more than a million sites with cave paintings and rock art throughout Africa, the Americas, Asia throughout Europe and Indonesia.  Did original artists intend to leave messages - paintings at some sites were added on or over older ones for tens of thousands of years.  Were they recording animals’ migration patterns, in case they did not live long enough to transmit information to their grandchildren? 

Archeologists have not yet to find the oldest messages from our ancestors because there is at least a 50,000 year gap in our discoveries of paint making and cave paintings.  A painting of a red disk at El Castillo in Spain is at least 41,000 years.  

40,000 years ago cave paintings on the Indonesian Island of Sulawesi were created.  The famous caves of France and Spain date back 35,000 years.  A tablet painted with ochre, black and white was discovered in southwestern Namibia dated to between 26,300 and 28,400 BCE. The “National Geographic” reported on discovery of engravings, estimated to be about 15,000 years old, chiseled into several sandstone (containing calcium) cliffs at Qurta 400 miles south of Cairo.  Earliest indications of the Egyptian civilization as we imagine it emerged about 6000 BCE.  

Through the dynasties, Egyptians perfected a painting technique we’d call “secco” on lime plaster.  

As I understand their processes, the tempera style paints were applied then coated with beeswax.  The wax was then steamed into the surface, usually sandstone, the composition of which includes calcium.  Aside:  “Encaustic paints” were invented during the Arts & Crafts movement of the 19th century.  

Because colors on the paintings inside the pyramids were protected from sun and temperature variations, scientists and artists can still see the actual colors and analyze the colorants used.  Those colorants include the infamous Egyptian Blue made by heating calcium carbonate with a copper-containing compound (metal filings for example), silica plus potash as a flux to temperatures around 1500 degrees F .  

That is just about the same temperature at which calcium carbonate calcines so they had the technology to make both white pigment and Egyptian Blue thousands of years ago.

Above see Lapis and Egyptian Blue

Egyptian blue pigment was considered obsolete because its formulae had been corrupted during the Middle Ages. However conservators have found evidence that throughout the Renaissance and into the 18th century, Lapis lazuli was often adulterated with Egyptian blue. If no one thought the pigment existed, would they suspect they were looking at a mixture of Egyptian/lapis blue rather than pure lapis lazuli?   Maybe secrets of the Old Masters do exit.  

calcium carbonate

calcium carbonate