Preservation 101: Paint

If plaster is as old as mud, well, so is paint.

Paint started out as mud- and was first used for very practical reasons involving insect repellent, camouflage, enemy intimidation, and it kept your dang hair out of your eyes. Then some bright spark figured out that river mud was a different color from swamp mud, and clay stuck better than sand. Voila! Prehistoric beauty palettes.

Natural materials such as red and yellow ochres, charcoal, and iron oxides were all used in prehistoric art, such as the magnificent cave paintings at Lascaux and Altamira. Other colors became possible by using plant, animal, and mineral dyes unique to different environments and purified through chemical processes.

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The Hall of Bulls, Lascaux, Dordogne, France

Art historians are not entirely certain when art made the transition from religious expression to pretty picture on the wall, but it seems logical that this corresponded with the Neolithic Revolution of ca. 10,000 BCE. During the Neolithic Revolution people made the conscious choice to transition from a less-intensive, but less-certain hunter-gatherer lifestyle to settled agriculture, which was extremely labor-intensive but also somewhat more likely to produce food in surplus.

Extra food = art for two very specific reasons. First, surplus food creates economies because farmers want to sell their extra food for other cool stuff. This means that you can do something else with your life other than farm and you’ll be able to eat as long as farmers want whatever you make- i.e. pots or knives or pretty things. Second, agriculture forces people to stay generally in the same place which means people will build permanent dwellings and keep stuff. If you’re always moving, you don’t have a lot of belongings and you don’t expend a lot of energy to build housing. Settled people tend to build sturdy, long-lasting homes and accumulate a lot more stuff over their lifetimes (just ask my mother).

Building technology improved over time as more people built permanent dwellings, and eventually people figured out the different properties of stone, clay, mud, straw, wood, and other materials. Two things happened along the way, with significant overlap in their applications: plaster and paint.

Plaster, as previously discussed,  serves lots of useful purposes, but is generally applied as a smoother, finer, denser coating over a coarser building medium. It can keep out the rain, keep heat in, look pretty, and is a handy sacrificial material that can easily be repaired when Nature inevitably tries to undo what man created.

Plaster comes in as many colors as there are types of temper, though generally most lime plasters tend toward shades of white, gray, and pale yellow. The ancient Egyptians found this boring, so they brightened up their walls with paintings a secco, meaning pigment applied to dry plaster with a binding medium such as egg (tempera) or oil. Later, ancient Mediterranean peoples such as the Minoans figured out that painting on wet lime plaster or buon fresco had a more permanent effect because the chemical reaction that hardened the plaster also cemented the pigment within it.

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The famous Bull Leaper or Toreador fresco from the ancient palace at Knossos, Greece, ca 1500 BCE

So between the Neolithic Revolution (10,000 BCE) and early recorded history (2000-1000 BCE) people figured out paint and plaster, then applied them to their homes as decorative elements. What else do the ancient Egyptians, Greeks, Minoans, Phoenicians, and Cretans (as well as the Chinese and Japanese, other pioneers in paint technology) all have in common? A navy.

What does paint have to do with naval sea power? Think about it. What were some of the earliest used of paint as personal adornment? Bug repellent and enemy intimidation. Some intelligent individuals in the ancient world painted their ships to scare the bejeezus out of their enemies and figured out that (eureka!) paint helped to prevent damage to the wooden hulls from salt water, dry rot, and “fouling” or accumulation of biological stuff such as barnacles and water weeds. Plutarch is one of the earliest to record recipes for paint-like ship coatings that involved silicates, rosin, pitch, tar, and… lime!

Why lime? Because, just like in a fresco, the hydraulic properties of lime mean that anything in the mixture is permanently incorporated within the hardened finish product and this reaction happens in the presence of water. So combine lime with something slick like rosin, oil, or finely crushed stone and you get a very dense, near impermeable coating.

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This colorfully painted ship is depicted in a mosaic found in the Villa Romana de Casale, Sicily (ca 325 CE)

Thus we have leapt from pretty pictures to extremely important seafaring technology involving wood as a primary construction material. Very very helpful to Mediterranean mariners, but not really applicable in Mediterranean houses which a) more likely to be built of stone or concrete and b) if they did have timber framing, were generally in a dry climate not conducive to rot.

Then those Romans went a-viking into Northern Europe where everything was built of timber and it rained all the damn time. Sometime around the beginning of the first millennium, whitewash entered the historical record- either because the Romans figured out a solution based on existing naval technology or because they happened to write down something that had already been in use by the locals. Whitewash or limewash is a solution of lime, water, and a temper such as chalk or flour that hardens into a slick coating with mild antibiotic properties. This handily prevents mold and protects the exterior of wooden buildings from rot damage.

Unfortunately, it is impossible to know when or if colored houses were a fashion because while limewash does retain pigment like a fresco, most natural pigments fade very quickly when exposed to sunlight or freeze-thaw cycles. We do know that the Romans liked lots of color in their environments and that, like so many other Roman technology, innovations in paint went dormant between the fall of the Empire and the Renaissance. Except, notably, in the seafaring Scandinavian countries where paint was used with equal frequency on ships and houses. Note the traces of pigment on the timbers in this medieval Norwegian church-

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Borgund stave church, Sogn og Fjordane, Norway, ca 1200 CE

The next innovations in paint technology happened during the Renaissance, when decoration became a symbol of wealth. Those stunning Italian cathedrals? Mostly frescos, done using the same technology invented by the ancient Cretans. Artists began experimenting with pigment and demand for paint colors became a major industry- demonstrated by the success of the color “cochineal” (a rich crimson) invented by the Aztec and brought to Europe by the Spanish in the 16th century. Other popular “new” colors were arsenic sulfide (verdigris, Northern Europe), lead-tin yellow (Northern Europe), copper carbonate (malachite and azurite, Near East), and green earth (an iron-based compound, Northern Europe).

The reason color and decoration meant wealth was because these new paint colors were incredibly expensive and impractical for painting large spaces. It is not unreasonable to equate painting a Renaissance chapel ceiling with covering the whole thing in gold leaf- the gold might actually be cheaper.

Us plebes weren’t to get color in our lives until the Industrial Revolution, when clever chemists figured out two things- a) that (often toxic) industrial byproducts came in pretty colors and b) that flax seed oil (linseed oil) was an effective polymer, meaning that it dried into a slick coating similar to limewash.

Mix toxic chemicals with a good polymer and now you have cheap, mass-produced paint! Why is there a market for cheap paint? Because of a massive housing boom related to the Industrial Revolution which caused thousands and thousands of cheap wooden houses to be built for workers, many on the outskirts of major Northern European cities where (just as the Romans noticed) it rains all the damn time and additionally, there are lots of corrosive chemicals being spewed into the air. The hardened polymers of paint and limewash helped protect wood and interior plaster from damp and deterioration, and of the two paint was more popular because white limewash showed all that dang coal soot.

Takeaway: paint was invented along with plaster, but found its most widespread application (pun intended) on wood, used to protect the exposed wood from environmental damage. This is why painting your wooden surfaces carefully and often prevents rot damage. It also works outstandingly well on metal surfaces, such as roofs and ship hulls.

 

Next time: How to Paint Properly (and Not Destroy Your House)

 

 

 

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One response to “Preservation 101: Paint

  1. Pingback: Preservation 101: Rot (Which is Not Hot and Looks Like Snot) | buildings in your history·

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