How to Make a Bad Painting Part 2

Summary: Making artwork is a combination of multiple skills. Experience and practice in rendering subject matter, determining a suitable composition, interpreting the subject stylistically and finally, transferring the ideas into the medium of your choice.  Part two of this  essay will focus on the optical properties and characteristics of various oil paint extenders and how lead, resin additives have and can still impact impact painting longevity.

Sir Joshua Reynolds and painting mediums

What was the allure for Reynolds and why do these materials still get used by contemporary artists?  I have pondered this for several decades and always come to the same conclusions.

A: Inexperienced artists look for guidance from old painting manuals to materials to select what they need to create paintings. B: Artists gravitate toward experimentation and the exotic, mysterious nature of painting medium that contain ancient ingredients that fulfill their desire to harness a magic media that will create amazing works of art.  Part of this relates to the long-standing quest to find the “Secret Medium of the Old Masters.”  Painting treatises are filled with the hunt to find the medium and preparatory method that Rembrandt and his contemporaries used to create the warm glow and luminosity found in their artwork. 

Contemporary literature by reputable sources explain that time was the “secret medium.” The process of aging of paint creates transparency that allows light to penetrate and reflect color. A viscous, amber colored, lead-varnish, wax concoction ,can simulate the paint aging process.  However, a price must be paid for artificial, simulated aging. The medium creates an unstable, paint layer subject to wrinkling, cracking, darkening and eventually to failure.  Despite being told time and again that varnish mixed with paint makes a painting difficult and perilous to clean once it ages and darkens, artists still believe they can cheat the premature death of their artwork by using varnish and related mediums in their paintings.

Some contemporary art material companies fulfill the desire of artists to employ exotic or questionable mediums.  They even use the term “megilp,” a term that any 18^th century artist would recognize.  However, several art material companies smartly formulate safe modern chemical media to fulfill the desire to use a paint extender.  Alkyds have filled that niche with a variety of accelerated and non-accelerated drying mediums.

To elaborate further, if the goal is to augment oil paint to create luminosity, modern alkyds or even traditional drying oils (linseed, poppy, walnut, safflower) will perform this task well.  These media will allow light to penetrate and bounce around pigment particles to create a similar type of “luminosity” that appears to emulate the “secret old master” mediums, but without the inherent vice attached. If quick drying is desired, many modern media contain drying ingredients to speed oxygen induction.

Going into a bit more depth, the influence of various media to create luminosity has to do with the refractive index of materials. Simply put, related to paint films, refractive index is how much light bends and goes deeply into a paint layer as opposed to being scattered and bouncing off the surface of a painting. Low refractive index numbers indicate less luminosity caused by scattering and less light penetrating and bouncing around.  Higher refractive index number do the opposite and display more light penetration.

The refractive index of linseed oil is 1.48 and 1.49 for stand oil.  Other vegetable drying oils like poppy and walnut have a refractive index of 1.47.  Dammar varnish has a refractive index of 1.52 – 1.54.  The compound mixture discussed as megilp (related in formulation to the modern iteration called Maroger Medium) has a reflective index of 1.50 – 1.52. 

Here is where it gets interesting. Alkyd mediums have a refractive index of 1.50 – 1.54.  An artist who uses megilp, and especially an artist who makes megilp at home, needs to consider if the risks involved in being exposed to lead, turpentine, dammar and drying oil are worth the effort when alkyd media have the same or a slightly better refractive index.  Long-term exposure to the toxicity of the aforementioned materials along with the bad outcome as displayed in paintings by Reynolds, seems to answer that question.  

The key point is that complex 18^th century megilp mixtures hardly perform any better than single plant species drying oils and even equal or less than alkyd and oil mixtures.  It comes down to a belief that exotic mixtures are doing something different than simple plant-based drying oils and alkyds.

In many cases, it is the method of application that influences the use of exotic media.  Artists who paint by “sandwiching” layers of oil paint alternating with megilp or by mixing oil paint and megilp run all of the risks associated with the breakdown and premature aging of the paint surface that has been well documented by museum conservators. 

Some artists have a burning desire to experiment and once introduced to lead, boiled, solvent infused, resin varnish mixtures, they feel they have tapped into something special. This desire stems from the discovery of old painting manuals that describe the formulation and use ancient media. The images and style of writing beckon artists to “Use the force” and “Come to the Dark Side” with attractive steel or woodcut images of paint tubes, and phrases in foreign languages that connote mystery. However, we all know how all this turns out. Aside from the problems old media formulations will cause in both the near and distant future, health risks using, and more importantly, in making these questionable media themselves, should convince artists to abandon the task.

No health professional versed in toxicology will condone or proclaim it safe to be in the presence of boiling lead infused oil and volatile solvents without industrial strength air handing and serious personal protective gear. Yet, these practices still exist to some extent despite a growing number of artists abandoning the use of any solvents, even in cleanup, within their studio space. The risk/rewards are just not there.  Painting and staying healthy should be a primary goal, rather than stirring a toxic witches brew over a hot fire.

An understandable  gap exists in our general education. While students in school take chemistry, biology and health classes, a typical curriculum does not appear to focus on the toxicology of chemicals people come into contact with products purchasable from a hardware store.  This includes a host of lawn care products as well.

We seem to obtain knowledge about toxic substances by word of mouth or reading the fine print on containers.  The news provides some information occasionally when an accidental spill occurs.  Somehow, we are supposed to know what is harmful and what is not.  While smell is a good indicator, it is not totally reliable. Plus, we can rationalize that occasional exposure to toxic chemicals should not cause long-term harm. Avoiding harmful materials can be annoying because we must think and work out strategies to eliminate exposure.

For me, the term that encapsulates the use of questionable mediums comes from the German word for a painting medium.  The term is “malbutter.”  Read literally, without translating it into German, pretty much sums up and warns that the use of exotic media will end badly.

The Syntax of Color

Keywords: mediums, refractive index, linseed oil, alkyds, lead, turpentine, how to make a bad painting, comparison of mediums, toxic art materials,