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Making Pottery

Part one: Making pottery, by Jeff Martin

When analyzing prehistoric people in the American Southwest, How do we define different cultures? Some people might say by religion or ethnicity. Indeed, that is partly correct. However, in archaeology we go beyond the simplistic methods of identification. Rather we examine oral tradition, migration patterns, language, kinship groups, foods, architecture, and ceramics. Moreover, because of the qualitative nature of ethnographic research, anthropology has gained tremendous incite into the prehistoric past through modern descendants. For the purpose of this entry, I want to focus on the aspect of identification through ceramics. Later, we will discuss how to make and fire pottery.

Long before European contact in Arizona there were highly mobile hunter/gatherer groups recognized as the Clovis and Archaic people. Clovis people hunted large game such as mammoth, whereas mid and late archaic groups hunted medium sized game. After the Archaic period we see new groups of people emerge recognized in archaeology as the Hohokam, Pueblo, Sinagua, Prescott, Salado, and Mogollon cultures. All of these cultures did not just randomly pop up in the archaeological record all at once. Rather there is a gradual transition that stemmed from archaic people. Whats more, each group has similarities and differences in material technologies. Some similarities involve the production of maize agriculture, the use of shell decorations, bow and arrow cross-section and style, and the utilization of pottery. Some differences include how maize was produced, how a shell decoration was assembled, and how pottery was made, decorated, and produced.

Over the past fifteen years I have had the opportunity to observe and handle thousands of pots from all over the world that sit in museums, private collections, and storage facilities. Many of these ceramics are masterfully crafted and show significant wear from daily use and weathering. While I have seen Mayan vessels that are absolutely stunning, and Mimbres bowls that give us a glimpse into prehistoric daily activities, the most intriguing pots come from the early Hohokam Colonial period. These red-on-buff ware pots show interior designs of hatched animals, design ticking, shallow scored exteriors, and trailing exterior lines. In addition, we also see some elements of Mesoamerican influence, ideology, and connections displayed in red-on-buff pottery.

In the Hohokam region pottery was created using a paddle and anvil technique, whereas in the pueblo region pottery was manufactured using a coil and scrape method. Depending on the vessel observed, the average person would likely not be able to see the difference between a jar made with a paddle and anvil technique compared to a coiled and scraped pot. This is because the potter made sure the jar was smooth and held together with absolute seamless perfection. However, when observing a corrugated Puebloan jar from 1000 A.D and a Sacaton Period Hohokam jar, there are clear observable differences. These differences do not alter the integrity or basic function of both vessel styles.

As we shift gears on how to make pottery, it is worth mentioning that everyone has a different style of production; even in the same form. For example, if a person makes pottery using a paddle and anvil technique, they might do things a bit different than another person who makes pottery using the same technique. For me, I like to use a paddle and anvil method combined with coiling and scraping. This means when constructing a pot, I will use both southwestern methods of manufacturing with the goal of producing a single vessel.

Before I get too far into pottery production, I want to briefly mention tools used for making pottery. Once again, depending on your style, the type of pot being made, and vessel size, tools will have variation. Below is a list of the tools Kiowa and I like to use and recommend.

– black trash bag
– cotton cloth and pillow case
– pookie (cloth or clay)
– wood paddle and stone anvil
– gourd scrapers
– smoothing stone
– sharp flakes of obsidian or other trimming tool

The first thing you need to do is gather clay and process it. My recommendation here is to get in contact with a local potter or museum and ask about residual clay sources in the area. Many residual sources are already tempered and to not require the addition of crushed rock, sand, or shell. Keep in mind however, potters keep residual sources quite secretive and you might need to set up a trade. Also worth mentioning is each clay body is different and might be tempered with a different material. One of the clay bodies I gather from is 5,000 feet above sea level and tempered with a phyllite composition. Many potters will tell you clays from the mountains are poor quality compared to clays found at lower elevations. I tend to agree, but also disagree. While mountainous clays tend to crack when too much or too little moisture is applied, you can drastically improve the clay quality by processing it using alternative methods such as slurrying.

Some potters will gather the raw clay in a bucket and begin to tunk or crush the clay with a hammer stone. They will sift the clay in a mesh sifter or a basket and add water to create a paste. While this method will work, I like to slurry the clay. As mentioned briefly in the previous paragraph, this alternative processing method improves the quality of mountainous clays quite drastically. Once you have about 2 or 3 gallons of clay sifted, fill a 5 gallon bucket with about 4 gallons of water. Add the sifted clay to the water and stir the mixture with a stick. After stirring for about 5 minutes, pour the mixture into a large pillow case and tie the top secure. Next, dig a pit into the earth and place the pillow case inside. At this point you want to wait about 10 days to allow the water to fully hydrate the clay.

After 10 days you will notice the clay is hydrated and lumped into a single brick, remove the clay and place it into a black trash bag, twist the bag and allow it to age for about 2 additional weeks. When aged you will notice the clay is not too wet but also not too dry; it should feel like a slightly stiffer play-dough. Now place the clay on a solid flat surface and wedge the entire brick for about 10 minutes. Wedging removes any excessive moisture, makes it more pliable, removes air pockets, and creates a uniform consistency. At this point you are ready to make the pot.

Begin by placing your damp cloth around the form bowl. Next take a hockey puck sized clump of clay (this can vary depending on the size of pot being made) and flatten it into a thick tortilla like patty. Place the flattened clay on top of the form pot and make sure it is centered. From here I recommend checking the edges and trimming any low or sagging spots. Now wet the paddle and thin the clay from the center point to the edges. Once again after each round of paddling, trim the low spots of clay for a symmetrical consistency. The next steps are to add coils to the clay and continue to build the walls of the pot.

Pinch off about a golf ball size amount of clay and roll it between your hands as if you are forming a snake. Place the coil on the edge of where you trimmed (the wall) and smear the coil onto the clay body. After you coil around the entire circumference, wet the paddle and thin the coil. As you paddle and thin the coil you will notice the clay is naturally pushing itself down. Essentially, you are building the walls up when the pot is flipped over. After you finish paddling, wet your smoothing stone and slide it across all outer parts of the clay. Smoothing the vessel will further help bond the clay together, get rid of potential air pockets, and smooth out any rough spots. Repeat the process of coiling, paddling, smoothing, and trimming until you reach the bottom of your form pot. Depending on how much moisture you applied and the humidity levels in your environment, let the pot sit for about 15 – 35 minutes. This allows the pot to firm up a bit and hold its shape when removing if from the form and proceeding to the next steps in manufacturing.

Well, you made it to this point. Now here is where things get tricky for the beginner. Just keep in mind, the more pottery you experiment with, the better you will get. When I first started making pottery, I let my frustration get the best of me. There were times when I would swear at the pot and throw the clay against a wall  Hey, its just part of learning. Right? I digress. Take your form pot and clay body and turn it over. While supporting the bottom of the clay body, remove the form pot and damp cloth. Place the newly worked pot on your cloth or clay pookie and pinch the rim to a point around the circumference. Now make a few coils that are thicker than the rim of the pot and place them on the top of the pinched surface. Smear the base of each coil on the inside and outside of pot. Use your gourd scraper to smooth out the coil seams while using your hand to support opposite side of the wall. Next use the paddle and anvil along the coil and paddle the clay up. This will thin the coil and blend it into the vessel nicely. After a couple of passes around the pot using the paddle, wet your smoothing stone and swipe the inside and outside walls. Swiping the surface will smooth the uneven surface and remove possible air pockets. Just like before, you will likely see the rim is uneven and mountainous. Simply trim the high spots and repeat the previous steps starting with pinching the rim.

Once you have a desired vessel size and shape, it is time to finish the pot and prepare it for firing. Examine the pot’s rim and make sure it is even without high spots. If you see a high spot simply remove clay or fill in the valleys with additional clay. When the rim is even, I recommend wetting your fingers and smooth the rim from any lumpy spots. From here, store the pot in cool shaded place and allow it to fully dry. Depending on your location, this can take one to three weeks. After the pot is dry you can choose to keep the pot as is, polish and paint it, or just simply add a polish. To polish a pot, use a slick and smooth stone such as rounded polished obsidian. Wet the stone and buff the pot’s surface. This process is time consuming, but adds a beautiful look and we do find polished sherds archaeologically. Painting the pot brings the vessel to life while displaying a high sense of creativity and artistry. Depending on how you want to fire the vessel, will determine the paint you use. When firing in oxidation iron oxides such as hematite work well. With buff clays, hemetite will fire red, deep red, or purple/red. However, when firing in reduction, bee-weed, sunflower, and mustard sugar extracts give a beautiful black color and adhere to the pot much better.


(Above left: Kiowa’s bowl) (Above right: Jeff’s bowl)

Part 2: Firing pottery, By Kiowa Sage

Clay is one of the most malleable materials on the planet, but when exposed to extreme heat, chemically, it changes into a permanent ceramic. This process is called vitrification. This change is what makes pottery valuable as a means of use to cook, disinfect water and store food. Fortunately due to this, pottery sherds are one of the most abundant artifacts recorded in the archaeological record because of their ability withstand decay. Allowing for a lot of valuable information to be collected from a single sherd.

Build a preliminary fire, ideally in a sandy wash or somewhere fire safe, and place your pots along the perimeter. This initial fire’s purpose is to slowly heat up the pots and build a hot bed of coals which will be the base of the final fire. Pottery needs to be heated up prior to the final fire, in order to ensure the pots don’t explode or crack due to thermal stress. Clay is hydroscopic, which means that it retains trace amounts of moisture, like a sponge, it absorbs excess moisture from the environment. When heated abruptly, the moisture steams rapidly with nowhere to escape, causing blowouts called “spalling”. As your preliminary fire burns down into coals, place “kiln furniture”, a.k.a volcanic or granitic rocks on the coals to serve as a place to lay your pottery in the kiln. Let your pots sit on the stones and heat up slowly, this initial heating of the pottery is crucial in ensuring your pottery won’t crack or blow out during the firing. Place droplets of water or saliva on the pots in the kiln, if it sizzles off the surface the pottery is ready to be fired.

Oxidation firing is where plenty of oxygen is accessing the kiln area while the fire burns down. Much like making a pot, oxidation firing requires thorough understanding of how to work with and manipulate clay. Picking up from the previous paragraph, stack wood around the pots tightly, using smaller sticks along the interior and larger branches on the outside in a conical formation. Utilizing fuel that is no bigger than the diameter of your wrist/arm will suffice. As the wood burns down and peak temperatures are reached, approximately 900° F, the iron in the clay oxidizes to a reddish/orange color. Allow the coals to burn down to ash before pulling the pots out of the fire. Once the pots are completely cooled down, rinse the ash from the vessel and applaud yourself for a successful oxidation firing.

Reduction firing usually requires a pit to be dug as opposed to an oxidation firing, which is usually on the surface or in a shallow pit. The initial process is the same in the beginning stages to firing in oxidation. However, when the fire reaches its peak temperature, you bury the kiln area with dirt; rapidly suffocating the kiln area of oxygen. This firing style is a little trickier, as you need to bury the kiln within a small window of opportunity before the pots have a chance to oxidize. This firing style is usually employed when dealing with painted ware, typically with organic paints that will burn off easily when too much oxygen is allowed in the kiln. Organic paints are made by rendering (concentrating the sugars) various plants such as sunflower and rocky mountain bee plant via boiling into a syrup. If fired correctly, the paint is able to burn off but leave a carbon stain which gives a dark black color to your bowl design.

(Above left: Kiowa’s oxidized pots) (Above right: Jeff’s reduced pots)

Through time and space pottery was an important aspect of the traditional prehistoric lifestyle. Across the American southwest we see many different shapes of pottery that served a basic necessity for daily living. Whether the pot was used for storing food in, or used for eating, we understand the tradition of making pottery lasted until we lose track of many prehistoric cultures around 1450 A.D. Furthermore, it is critical for the anthropologist to identify cultures using ceramic analysis. We must look beyond basic methods of cultural identity. Rather we must examine the abstract nature and methodology of creating, producing, and distributing ceramics. Indeed, each sherd tells a story of where it was produced, who produced it, what materials were used, and how it was constructed. Although in modern day we can apply scientific methods of identification to gain vast knowledge from a single pot sherd, there is still a mystery behind some of the abstract designs displayed on pottery across the American southwest. Finally, in closing this article we want to encourage you, the reader to experiment with making ceramics. Remember each pot is a learning curve. In the beginning frustration will set in. However, after trial and error you will become accomplished in a skill that is still practiced by decedents of prehistoric people.

Authors,
Jeff Martin
Kiowa Sage