Pottery Production at the Ceremonial Site of Pachacamac: A Visualization of the Mold-Making Technique

  • by Delaney Keenan
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Introduction

The consumption of food and drink is often related to identity. The types of food or beverage we consume can be naturally dictated by the place in which we live or our associated natural identity. Location can dictate which fresh food we have access to, for example vegetables such as corn in the Americas or the production of rice in parts of Asia. Each cuisine has its own methods of production and consumption, and unique tools for these purposes. These tools for production could range from specific farms tools, to cooking vessels for boiling, or oven technology. Each food is an art and has tools specific to different cultures of the world. The handmade production of unique cuisine tools can feature designs and iconography specific to a location, helping to propel a national visual identity. Most importantly, we must recognize the mass-production of cuisine tools and the labor and technical skill of men and women needed to create them.

Reconstructing the past is a way for modern-day people to visualize past tools for food and drink consumption, as well as understand the labor that went into making these vessels.

By peopling the past, we give agency to the past people who created objects we see in museum settings today, as well as highlight the objects as items for everyday use, not just something seen on a museum storage shelf. Visualizations of the past can be in a variety of different forms such as artist reconstructions based on forensic data, photographs of objects found at excavation sites, and 3D models based on strict research of archaeological findings and reference images. The use of various media to present the past for modern audiences has many benefits, but at the same time potential problems associated with stereotyping, gender bias, and belittling the contributions of these people to our global visual culture. Gender bias is relevant to discussions about reconstructing back food technologies and the people who created the cuisine tools, as modern notions about women’s role in cooking could infiltrate our reconstructions. Ideas about gender bias in historical reconstructions has been written about by Joan Gero and Dolores Root (1990) in relation to National Geographic Magazine, but their ideas are relevant to a wide range of media.

Pottery at Pachacamac

Pachacamac is an archaeological site in the Andes, located near today’s modern city of Lima, Peru on the western coast bordering the Pacific Ocean. Scientific excavation at Pachacamac was pioneered by University of Pennsylvania Museum of Archaeology and Anthropology (Penn Museum) curator Max Uhle in 1896. His meticulous research at Pachacamac brought thousands of objects to the Penn Museum and documents the importance of Pachacamac to Andean peoples. By late pre-Columbian times, Pachacamac was a pan-Andean ceremonial center featuring prominent temples for worship by the Inca people but the site’s local importance extends at least 1000 years earlier (Eeckhout 2013). The population numbered in the thousands, but during ritual ceremonies, many more people would come as worshipping pilgrims and need access to shelter, food, and drink (Eeckhout 2013). Pachacamac and the variety of excavated objects we have from that site helps us to visualize what life would have been like for these people and attempt a reconstruction of their rich visual culture through archaeological material record, architecture, spaces, and site layout, in addition through historical accounts and ethnography of descendant communities. The Peruvian government has protected Pachacamac and the site was recently declared world heritage by UNESCO, so future generations can study, admire, and learn the ceremonial center, the past people who inhabited the place, and appreciate their technology, artistry, iconography, and aesthetics.

As a pre-Columbian ceremonial center, Pachacamac welcomed visitors from the region and beyond to partake in festivals. In addition to music, theater, pageantry, and sacrifice, key elements of festival culture are the consumption of food and drink, particularly that of the Andean chicha or maize beer which would have been produced in large quantities at Pachacamac (Bray 2009). Food and drink needed to be stored and transported in vessels made from pottery (Hayashida 1999). Food and drink were important in Inca culture related to politics and gender, and the functional and culinary significance of pottery in the Inca culture is discussed at length by scholar Tamara Bray, who also seeks to highlight the importance of women in the negotiation of state power through pottery vessels. As a ceremonial site, ideas about reciprocity and hospitality in Incan states is important to understanding the large festivals that would have been organized at Pachacamac. The production of chicha was a long and complex process, which required large pottery cooking vessels for boiling, large pottery jars for fermentation and storage, a large quantity of large and small jugs, bottles, and cups (Bray 2009). People from the Andean region created a variety of standardized, yet highly distinctive vessel forms, which scholars such have tried to catalogue. Pottery, chicha, food, and politics was intimately linked in Inca cultures, and the pottery produced at Pachacamac is linked to the empire as a highly recognizable, emblematic imperial style.

The demand for vessels to be used for food preparation, cooking, serving, and storage and the production of chicha meant that potters serving at Pachacamac and throughout the Inca Empire produced an abundance of highly standardized pottery, some of which resides at the Penn Museum due to the excavations at the site by Max Uhle in 1896. Andean Pottery was created using two different techniques: coil-making and mold-making. This project seeks to understand and visualize the latter technique of making pottery with molds.

Mold-Making Technique

Archaeologist Christopher Donnan has written extensively about the production of pottery in the Pre-Columbian Andes, and much of his scholarship has shaped my understanding of the mold technique (Donnan 1992). Excellent sources of clay suitable for making ceramics were available throughout the Andes, helping to understand the quantity of pottery which could have been produced there due to material availability. The most common type of clay used was terracotta, which contains iron and is naturally dark brown in color. Terracotta would have commonly been used to produce gray-black ceramics in this region. The initial steps of the pottery production process are mining the clay from riverbeds, drying and grinding the raw material, screening for debris and rock, mixing with temper and water, and then forcing the air bubbles out of the dense mixture (Donnan 1992).

The mold technique uses press molds into which potters press soft clay to the desired thickness of the intended vessel wall (Donnan 1992). Most commonly, two piece molds were used to create the front and back of the main body of a globular vessel or the two halves of a chamber to be combined as a double-chambers spout and whistle (Donnan 1992) (Figure 1). Some vessels have identical patterns on both sides. In these cases, a single mold may have been used for both sides to insure the symmetry of the vessel. Various elements such as the spout could also be formed using these molds, or outside elements such as handles could be attached after the molding-process on blackware pottery. The use of press molds facilitates the rapid and efficient production of multiple copies of pottery of the same form, which Donnan finds were generally of elaborate three-dimensional forms with low relief decoration (1992) (Figure 2). Overall, mold making required less time and skill than creating pottery through the coil-making technique. Donnan believes that this molded pottery was “mass produced by potters who were more interested in the quantity than the quality of their product” (1992: 17). Mold techniques were also used to create small anthropomorphic figurines which could not be made as effectively using the coil-making technique (Figure 3).

Pottery was decorated with a variety of techniques from stamping to slip painting to burnishing. Painting and burnishing techniques to get the smooth body surface texture. To achieve a smooth surface texture, a craftsperson could rub a smooth stone or bone on the leather hard clay surface while still moist (Donnan 1992). The impact of burnishing a vessel is that the surface is smoother and polished. The various techniques of texturing of the surface of a vessel could be done in the mold or after the clay was removed from the mold. Before the clay was completely dry, texture could be added by incising, engraving. punctuating, scraping, stamping, and/or combing (Donnan 1992). Excision was another method used to cut away “the surface around an area that was to remain in low relief” (Donnan 1992: 18). These methods of texturing could be used to refine the dot pattern imparted by the mold, to ensure the texture pattern was to the craftsperson’s liking before the pottery was fired (Figure 4).

Firing techniques are also a way to create different surface colors and textures on the pottery vessels. Black ceramics were produced using smudge or reduced firing in shallow earth pits, surrounded and covered with fuel such as wood, animal dung, and compacted leaves (Donnan 1992). In this technique, first oxygen freely circulated around the objects until they reach peak temperature; then more fuel is added and the pots are buried with sand or soil. Burying the kiln in this second stage with the new fuel and pots together creates an intense smoke and a reduced atmosphere with little oxygen. The direct contact of the thick smoke and the pottery forced carbon into the vessels, which would often give the final product a metallic appearance. The smoke is a key factor in creating pottery with gray or black coloring, and the pieces created in this way are referred to as smudge blackware (Donnan 1992).

Black color could also be added on pottery using an organic black pigment of extracted plant liquid which was painted on the vessel. At first the liquid would appear clear when first applied but when the vessel was heated over an open fire causing the organic material to scorch black. The craftsperson had to carefully regulate the temperature because too low would not turn the color black, and too high would burn the organic material off completely. This method would be applied to various types of pottery either to supplement and darken the already black smudge blackware or color a vessel that was not made as black.

Max Uhle recovered a pottery vessel during his excavations at the site of Pachacamac in 1896 for the Penn Museum (Uhle [1903] 1991). The vessel 31822 was found in the area Uhle called The Northwest of Town, and is dated between 1476-1534 CE. The vessel measures 31 centimetres in height and 22 centimetres in maximum diameter. The surface features 5 zoomorphic designs on the top outside of the vessel, as well as an organized dot pattern. The basic form of the vessel features a globular body, two handle openings that join together in one spout, and two side offshoots for decoration. The color of the vessel is black and gray. The exterior has a burnished finish and fire clouding is present on the body. Uhle includes a chapter about his excavations northwest of the center of Pachacamac between the inner and outer walls where this vessel was found (Uhle [1903] 1991). Uhle found blackware pottery in subfloor burials at what was probably an elite residence with some craft making activity present, and the vessels found were all consistent in style (Uhle [1903] 1991). According to Uhle, fragments of pottery are found everywhere in this area (Uhle [1903] 1991), and most of this pottery was black in color. My vessel features the iconography of animal shapes of a cat, pelican, and bird. Based on the shape, this type of vessel is a stirrup-spout bottle. My vessel also features markings of cloud firing, a surface discoloration which occurs during the firing process if oxygen meets the surface and some of the carbon deposited from the smoke is burned away. The result is that some areas of lighter color exist on the black pottery surface.

The process of making pottery with the mold technique was most frequently done by trained women (Bray 2003). Research has also shown that most often two techniques were combined to create any piece of pottery, which required craftspeople to have diverse knowledge and skills. Mold-making often was combined with modeling technique, such that the main shape and body of the vessel was formed with a mold, but the details such as decorative elements on the handle were modeled by hand as the craftsperson worked to manipulate the clay with their hands (Donnan 1992) (Figure 5). Spouts could be molded along with the body or handmade and added separately and attached to the mold-made body. Donnan provides evidence in his figures that spouts were included in some larger molds for stirrup-spout bottles (Figure 6). Due to the nature of molds as used tools to create pottery, a limited number of molds survive today.

Goals: Visualizing the Past and Recreating Objects

This project seeks to recreate pottery vessel 31822 from the Penn Museum and visualize the mold-making technique which was used to create this piece (Figure 7). The recreation of pottery is vital to giving agency to these objects and the women who made them—pottery such as this was vital to the everyday function and festivals at Pachacamac. By modeling this object, I will help to give pottery a context beyond the museum storage shelf as items that were used in everyday life at Pachacamac and produced by a skilled and knowledgeable craftsperson. This project is focused on re-creating the process of making pottery using molds, a technique often used to create smaller, ornate vessels or bottles of terracotta pottery. Pottery is an integral aspect of everyday life in Andean culture, especially at ceremonial sites such as that of Pachacamac. This re-creation is important for understanding the process of making objects that were vital and ubiquitous in Andean culture, vessels which were actually used intentionally, not just as art objects as the public often views them today in the context of a modern museum.

The pottery technique was often done by women and two-piece molds were the most common type. The actual molds are rare in archaeological excavations as they were never included as burial objects. Those molds that do exist are usually fragmentary surface finds at potter production sites (Figure 6). These vessels would have been fired in a traditional fire kiln, and sometimes they add black pigment for color, such as in the object from the Penn Museum. To color it, organic black liquid was painted onto the vessels after being fired and the vessel was heated again to adhere to the pigment to the pot. My goal is to model the complex pottery object and the mold used; and then position these objects in a local context with a female 3D human model who created this object to show her agency, knowledge, and skill to visualize and people the past.

Process: Research and 3D Modeling in Maya

My first step in the process of understanding and recreating the process of making pottery from molds at Pachacamac was to visit the Penn Museum collection with Dr. Erickson (Figure 8). I had the opportunity to study and photograph the object which helped me to understand the form, size, scale, color, construction, and surface texture. I also recorded the iconography of the vessel to understand its placement on the top half of the pottery vessel (Figure 9). Interacting with the vessel made me realize the unique features of its construction and complex surface texture. Through interacting with the object, I could understand the effort required to make such a vessel. I also visited the museum storage room to see other examples of pottery from Pachacamac for a greater appreciation of the different varieties of pottery, often related to the serving food or drink and as burial offerings. Seeing the objects in the Penn collection including drink cups and a whistling pot helped me to visualize different techniques of pottery construction. I took many photographs with scales of the vessel as reference images for my process of modeling (Figures 10, 11, 12).

Using the Autodesk Software Maya, I began to recreate this pottery object through 3D modeling. I began by importing a reference image with scale to Maya and created a scaled grid to match. I was used the Bezier Curve tool to trace the outline form of the body of the pot; then, I used the spin function to transform my outline into a three-dimensional object (Figure 13). Once the body was formed, I used the extrude function to create the handles and the decorative elements (Figure 14). I manipulated the extrusions using the move, scale, and rotate tools until the handle matched the references images (Figure 15). I then worked on creating the extrusions for the stirrup-spout and small bird figurine attached to the side to match the reference images (Figure 16). I then worked on shaping and smoothing the handle, spout, and small bird-like figurine (Figure 17).

Once the general shape of the pottery was modeled, I added a color to my vessel to match my references images. The color of my piece is unique so I used an image of the surface of the bottle I took at the Penn Museum as my imported color. The color is varied around the vessel due to the firing process, age, wear, and minor salt stains. I selected an area of the surface which was varied in color that represented the overall color (Figure 18). Once the color was applied, I modified the different levels of saturating and lighting to get a more accurate look (Figure 19).

This vessel has surface element designs including a dot texture on the top, and 5 zoomorphic figures: a small bird on the handle, two pelicans, and two cats. This vessel has a distinct raised dot texture. With the help of the TAs I used a polka dot image to create a bump map of this texture (Figure 20). First, I extracted the top half section from the vessel to separate the two different textured sections. I used 2 different materials to create this texturing. I textured using physical-based materials which interact with light (Figure 21). I scaled and modified the bumps to more closely match the reference images (Figure 24). Using the Arnold shader tool, I matched the specific characteristics of the vessel. I rendered the pot at this stage to see my progress. I used lighting and a basic background for presentation to stage my vessel with shadows to see the dots and the color (Figure 23).

At this stage in the modeling process, I realized that my vessel was likely made from a one-piece mold. The iconography and dot texture, as well as general shape, are symmetrical on both sides. Additionally, there is a visible seam on the side of the vessel where someone would have attached the pieces by hand using water to moisten the clay and their thumb to smooth it. Through close study of my vessel in the modeling process, I was able to understand the method of creation using a one-piece mold. Due to this realization, I decided to model my vessel with a one-piece mold as this would have been the original method of production, not a two-piece mold seen in many of my readings.

The next steps were to adjust my texture for more accuracy, add the animal iconography, and create the mold. Dr. Badler has informed me of a method to ensure that the texture from the vessel transfers to the model of mold: I would need to cut the vessel in half horizontally and create the raised bumps design using displacement mapping. Once the physical texture is applied to the vessel, I could use the Maya function of “Booleans -> Difference” to create a mold as a reverse surface of the vessel. After consultation with the TAs, I decided to use a different method to create a more accurate mold.

The first step to making my mold with the new method was to duplicate my pottery vessel, export the model, and transform it to one solid surface using the ZBrush program. After many failed attempts at using the Boolean-difference function, we determined that my vessel had too many faces, vertices, edges, and overall complex geometry that prevented the method from working (Figure 24). I duplicated my vessel after processing the geometry and exported it as an OBJ file (Figure 25). By solidifying the vessel into a less complex object in ZBrush, I could re-import the OBJ file and use that copy of my vessel with the Booleans-difference function (Figure 26). I was successful in creating a mold void with the shape of my vessel removed from it (Figure 27, 28). The next step was to apply the texture of the dots to the mold. After much discussion with the TAs, we determined that getting the physical bump texture to transfer from the vessel to the mold was not possible, so I had to apply the texture to the mold surface after using the difference function. I applied to dot texture to the mold by using the reverse of the same polka dot image I used for the dots on the vessel. I then used lighting to create shadows on the mold and vessel to highlight the distinct dot texture.

After this step, I produced another render of my model (Figure 29). I realized that I needed to adjust the lighting in my model (Figure 30). The added lighting made the model more visible in the render (Figure 31). At this stage I needed to smooth the edges of my mold and transform the faces to make it look less like a box. Model samples I saw during my research had rounded edges. I adjusted the mold by scaling different faces and edges (Figure 32, 33). I produced additional renders to evaluate my progress (Figure 34).

My model still needs some work to improve the details of this complex vessel. I have realized the great features on Maya and also the constraints put on me by time. The modeling of my vessel was ambitious due to the complex uneven surface texture of the designs which posed many challenges when creating the mold. I now recognize the difficulty in creating objects with complex physical texture. It is easier to replicate texture using images on the bump map, but it is more difficult to create physical texture using displacement mapping. Texture such as the small dots on my pottery vessel is complex to replicate in Maya. I traced the animal iconography of the vessel with the Bezier Curve tool in Maya (Figure 35) and then, I need to figure out how to apply the animal shapes of the design to the pottery model.

Results: An Appreciation for Mold Making Techniques and Pottery Vessels

My final model features the modeled vessel from the Penn Museum and a reconstruction of the mold used to make it. I had many challenges in creating this model, the three-dimensional bump texture elements and designs on the top half (Figure 38). Visiting the Penn Museum made me realize that this particular vessel has a complex texture which tricks the eye: the area within and surrounding the bumps is actually recessed, such that the top height of bumps align with the plane of the body of the vessel (Figure 39).

I want to stage the finished pottery vessel and mold in a scene with a female rig to show the important female agency in making pottery vessels in the Andean region at the ceremonial site of Pachacamac. This staging will allow a general audience to better understand the process of making pottery using the mold technique. This project has given me a greater appreciate for the construction of pottery and has activated these objects as items to be used in everyday Andean life (Figure 40).

Conclusions

The advanced skill of pottery technology is needed for the mass production of standardized vessels used for the preparation, storage, and serving of food and drink. Cuisine can be used in state production to unify regions and cultures, and for important ceremonial festivals related to national identity and religion. Vessels used in festival settings are important signifiers of craftsmanship present within a certain region.

References Cited

Bray, Tamara L.
2003   Inka Pottery as Culinary Equipment: Food, Feasting, and Gender in Imperial State Design. Latin American Antiquity 14(1): 3-28.

Bray, Tamara L.
2009    The Role of Chicha in Inca State Expansion: A Distributional Study of Inca Aribalos, in Drink, Power, and Society in the Andes, edited by Justin Jennings and Brenda J Bowser, pp.108-132. University Press of Florida, Jacksonville.

Donnan, Christopher.
1997   A Chimu-Inka Ceramic-Manufacturing Center from the North Coast of Peru. Latin American Antiquity 8(1): 30-54.

Donnan, Christopher.
1992   Ceramics of Ancient Peru, Fowler Museum, Los Angeles

Donnan, Christopher.
1965   Moche Ceramic Technology. Nawpa Pacha: Journal of Andean Archaeology 3: 115-135.

Eeckhout, Peter.
2013   Change and Permanency on the Coast of Ancient Peru: The Religious Site of Pachacamac. World Archaeology 45(1): 137-160.

Gero, Joan, and Dolores Root.
1990    Public presentation and private concerns: Archaeology in the pages of National Geographic. In The Politics of the Past, edited by P. Gathercole and D. Lowenthal, pp. 19-37. Routledge, New York.

Hayashida, Francis M.
1999    Style, Technology, and State Production: Inka Pottery Manufacture in the Leche Valley, Peru. Latin American Antiquity 10(4): 337-352.

Uhle, Max.
1903/1991   Pachacamac. University of Pennsylvania, Philadelphia.