What's That Stuff?: Pigments and Tempera Paint; The History and Chemistry Behind Pigments and Tempera Paints

Painters have used different types of mediums for centuries. There is oil, watercolor, acrylic, and tempera paint. One thing each of these paints have in common is the fact that each of their colors come from pigments. Pigments are usually minerals that are ground up and mixed with different binders to create paint. One medium whose popularity has risen and fallen through the ages is tempera paint. Created with pigment and a mixture of egg and water or casein (protein from milk) tempera paint has been a convenient medium used by artists for years.

Pigments are the properties in paint that give them their color. Pigments are various elements. These elements absorb and give off light, which humans then perceive as a number of colors. Different elements give off different colors. For example, the pigment “Cobalt green” is created when one gram of cobalt(II) chloride and five grams of zinc(II) oxide are mixed together and heated. The pigment that is then created gives off a dark green color. Pigments for paint are found it a ground substance very similar to thick sand. Not only made in sand form, during the Renaissance era pigments were dug out of the ground and shaped into chalk. In recent years, pigments have begun to be artificially created. One thing most people do not know is that pigments have different toxicity levels. The pigment “Emerald green” is very rare. It was created in 1808 as a replacement for Scheele’s green. This pigment was often used in paint as a color for houses but then found to be too toxic for use and was discontinued in the 1960s for causing deaths.

Tempera paint has been used for centuries starting in the Paleolithic ages. At that time they came from natural sources and were mixed with spit or fat from animals to create paint that was then used to paint caves. Later, in the twelfth century a monk used casein tempera paint. Casein paint has a casein binder. Casein is protein from milk. This was used for sometime then it’s popularity fell. Then, in the fourteenth century egg tempera was the primary medium for Italian artists. Many colors that were used are not in use today. One example of this is the color ‘Azurite’. It was one of the most prominent colors in artwork of the Middle Ages and during the Renaissance but was replaced when the color ‘Prussian blue’ was discovered. In the sixteenth century the popularity of egg tempera died down. In the late ninetieth and twentieth centuries artists began to study works of art and, wanting the same feel and look, began to use egg tempera again.

Binders are the item used in paint to make it stick to a canvas. The reason that this works is because most binders are something called a polymer. Binders can be many things including the protein from milk, fat, oil, or egg. Recently, there was a study conducted in which scientists created egg tempera paint the same as they did during the Renaissance era. They found that when applied to a canvas of some sort, these paints have certain properties (like the presence of lipids, proteins, and carbohydrates), which helped the paint stick to the canvas better. One example of how well an egg can work as a binder is simply found from doing dishes. Have you ever tried to wash your plate after having an egg for breakfast and find that it is a bit difficult to wash off? This is because egg sticks well and dries fast making it an ideal binder for paint.

When comparing tempera paint to oil paint one can see the differences very quickly. While oil paint is thicker while egg tempera tends to be much thinner. Oil paint dries very slowly and tends to look a bit murkier because artists often would mix the paints together while they dried. Egg tempera is known for being very vibrant and having a luminescent quality. With egg tempera you have to apply multiple layers. The good thing about this, however, is the speed at which egg tempera dries making this process go relatively quickly.

Pigments have been used for centuries and not only are good for paint but also different mediums of art such as chalk. Also, they are made up of different elements. Tempera paint is a popular medium and is convenient to make and use. Binders are what helps the pigments stay to a canvas and what, essentially, makes paint paint. There are perks and flaws to both tempera paint and oil paint but both are good for different styles of painting. Overall, tempera paints are a good choice of medium and have been shown to be so throughout the ages.

Uncle Tungsten

Uncle Tungsten Chapters 21-25
Chapter 21:
1) What is pitchblende?
Pitchblende is the element also known as uraninite. It is called this because of it’s mixture of other metals (such as lead and thorium) and the fact that it is very dark. It can be up to four times as radioactive as uraninite or thorium.

2) Describe the process used by the Curie's to separate the elements in pitchblende.
They first broke it down into groups and continued to brake it down until they came about a new element which they suggested be called polonium.

3) Why did the Curie's die so young?
Both the Curies worked with very radioactive materials and did not think about the effects that the radioactivity could have on them.

Chapter 22:
1) What is Sack's idea for a vanadium farm?
He would want to have many acres of sea meadows with sea squirts in it and then collect vanadium from the sea meadows.

2) What is the Milton society and what happened to it?
The Milton Society was a literature group at Sack’s school. It was unpopular and many knew it wouldn’t last.

Chapter 23:
1) What is the half-life of an element?
It is the characteristics of a radioactive element that is transforming.

2) How did the understanding of elemental decay affect the debate over the age of the earth?
Because many thought that the earth was too cold to sustain life before a certain time.

3) Why did the bombing of Hiroshima remind Sacks of Soddy and Wells?
Sacks thought of Soddy and Wells when hearing of Hiroshima because they were two large figures in nuclear power.

Chapter 24:
1) How did Moseley confirm the periodic table?
He used a cathode ray to get x-rays of each of the elements and then plotted the square roots of the elements against their atomic weight. This way, nothing could be missing or added.

2) How do electrons determine the elements chemical properties?
The electrons create bonding and therefore making up the chemical bonding.

3) How did Bohr's elemental periodic table compare with Mendelev's empirical periodic table?
They are almost the same. They both rely heavily on numbers for organization.

Chapter 25:
1) How and why did the affair with metals and their chemistry come to an end in Oliver Sack's life?
It didn’t happen suddenly, but he knew that one day he would have to go to medical school and become a doctor and his interest in chemistry slowly died out.

Outline

Pigments and Tempera Paints Outline
What’s That Stuff? Tempera Paint & Pigments
I. Introduction:
-Artists have used all different types of mediums for centuries. There’s charcoal, oil paint, even photography. One medium that’s popularity has gone in and out through the ages, however, is tempera paint. Created with pigments and a mixture of egg and water or casein tempera paint has been a convenient medium used by artists for years.

II. Chemistry of Pigments
-Pigments are perceived as different colors
-Elements absorb lights that have color and let off another color
-Different elements create different colors
-For example, the pigment “Cobalt green” is created when one gram of cobalt(II) chloride and five grams of zinc(II) oxide are mixed together and heated
-The color “Emerald green” was created in 1808 but then found to be too toxic for use and was discontinued in the 1960s for causing deaths.

III. History
-Pigments have been used for centuries starting in the Paleolithic ages.
-Pigments at that time came from natural sources and mixed with spit or fat
-A monk in the 12th century used casein tempera paint
-Egg tempera was the primary medium for Italian artists in the 14th century
-Pigments were not only mixed for paint but also used as chalk
-In recent years pigments have began to be artificially created
-In 16th century popularity of egg tempera died down as pigment mixed
with oil became more popular
-In late 19th and 20th centuries artists studied paintings of the past and egg tempera regained its popularity
-

IV. Binders
-Binders are used in paint to make the pigment stick to your canvas.
-This works because most binders are something called a polymer.
-Binders can be many things including milk, fat, oil or egg.
-Have you ever tried to wash your plate after having an egg for breakfast and find that it is a bit difficult to wash off? This is because egg sticks well and dries fast making it an ideal binder for paint.
-

V. Tempera Paint vs. Oil
-Tempera paints are thinner then paints such as oil
-Multiple layers must be applied
-Egg tempera dries very quickly therefore layers can be applied one right after another
-Oil, however takes much longer to dry and sometimes artwork using oil paint is murkier then the bright and luminescent quality egg tempera paintings come up with

Pigments & Tempera Paints Sources

http://homerepair.about.com/od/termsor/g/Pigment.htm

http://studiochalkboard.evansville.edu/p-pigment.html

http://www.watercolorpainting.com/eggtempera.htm

http://www.eggtempera.com/index.html

http://www.danielsmith.com/Learn/Articles/Making-Egg-Tempera.asp

http://www.eggtempera.org/

http://www.owlpen.com/paintedclothsessay.shtml

http://www.lindapaul.com/about_egg_tempera.htm

http://www.webexhibits.org/pigments/

http://www.brandywinemuseum.org/news_print/news058_print.html

http://www.learn-to-draw-and-paint.com/casein.html

http://www.springerlink.com/content/2707l65312430724/

http://www.paleolithic.com/

http://www.temperaworkshop.com/technique/technique4.htm