Appl Phys A (2013) 111:829–839 DOI 10.1007/s00339-012-7287-6 Fibrous twists and turns: early ceramic technology revealed through computed tomography Matthew Sanger · James Thostenson · Morgan Hill · Hannah Cain Received: 18 July 2012 / Accepted: 18 September 2012 / Published online: 3 October 2012 © Springer-Verlag Berlin Heidelberg 2012 Abstract While the emergence of pottery manufacturing is a wide-spread historical occurrence, and one that has gar- nered the attention of archaeologists for decades, we know very little about how these ancient vessels were created. Through the application of radiographic scanning and com- puted tomography this paper provides insights into the man- ufacturing techniques used by the earliest potters in North America. While x-rays have been used to investigate ce- ramic manufacturing techniques for decades, this paper pro- vides a reassessment of radiography in light of advances in both computed tomography and reconstructive software. 1 Introduction Archaeologists and historians have long been interested in the invention of ceramics around the world. The creation of ceramic vessels has been heralded as an important step within human history [9], yet we know relatively little about the techniques used to create these ancient objects. This pa- per will explore the possibilities of using radiography, in- cluding computed tomography (CT)-scanning technology, alongside new software applications, to reconstruct the par- ticular manufacturing techniques used by ancient potters. We will determine the applicability of both traditional and three-dimensional radiographic imaging to determine an- cient manufacturing techniques through an inspection of macro- and micro-structural characteristics of ceramic ves- sels. The benefits and drawbacks of radiographic techniques M. Sanger ( ) · J. Thostenson · M. Hill The American Museum of Natural History, New York, NY, USA e-mail: sanger@amnh.org M. Sanger · H. Cain Columbia University, New York, NY, USA will be discussed along with suggestions for further re- search. The creation of ceramic vessels requires the addition of tempering agents to the clay in order to survive the dra- matic shifts in temperature associated with the firing pro- cess. Numerous tempering agents have been used by pot- ters, including sand, shell, and grit. A less common addi- tion, but one integral to this paper, is the use of vegetative fibers. Fiber tempering is found around the world, often in conjunction with the earliest manufacturing of ceramics in a region [5, 10, 11, 19, 26, 28]. The source of the fibers varies by region and can include bark, moss, and shredded fronds. The fibers often become carbonized and do not sur- vive the firing process, leaving behind relatively long, thin voids within the finished vessel. Because of the dramatic difference in density between these voids and the surround- ing ceramic fabric the presence, orientation, and character of the tempering agents is highly visible using radiographic technology. The visibility of tempering agents is important to this project as prior radiographic and experimental stud- ies show that different formation techniques create charac- teristic internal structures within ceramic vessels. These in- ternal structures are largely visible by looking at the direc- tionality, regularity, shape, and boundedness of voids and temper within the finished vessel [3, 4, 16–18, 22, 24, 27, 31, 34, 35, 42]. Through experimental and ethnographic re- search, researchers have been able to characterize a wide range of construction techniques, including wheel throwing, paddle and anvil, and coiling and relate these manufacturing methods to characteristics visible within radiographic imag- ing. The present study focuses on fiber-tempered ceramics in order to capitalize on the radiographic visibility of this tempering technique. The samples date to the Late Archaic (5000–3000 B.C.) of the American Southeast, a time period