particular time periods and peoples. During this period, pottery was distinguished by thinner walls than preceding Woodland pottery. Common shapes are large plain cooking jars with strap or loop handles. A hallmark of Fort Ancient pottery is engraved decorations on the rim and neck of the vessels, consisting of a series of interlocking lines, called guilloché. As this design emerged with the beginning of the Fort Ancient culture in the region, scholars use it as a characteristic to identify the culture. Mississippian influences During the Early Fort Ancient period, grit (crushed stone) and grog (crushed pottery) were more often used as tempering agents, with ground mussel shells occasionally being used. With the passage of time, women increasingly chose mussel shells or a mixture of mussel shell with other agents as the tempering agent. The use of ground shells as a temper is a feature often associated with Mississippian cultures. This new technology was adopted in different Fort Ancient areas at different times. Its acceptance became more prevalent in villages, moving north and east from the Ohio River and the direction of the closest Mississippian groups in the southwest. With the change of temper, different vessel forms and decorations became more prevalent; several of them are also strongly associated with Mississippian cultures. Early Fort Ancient vessels were often jug forms with lug handles. By the Middle Fort Ancient period, bowls and plates were being produced more frequently, and artisans added strap handles. Negative painting (a decoration often associated with the Angel phase sites in the Lower Ohio Valley) and Ramey Incised designs (elite motifs associated with the Cahokia polity in Illinois) have been found on some pots. Others show a blending of different styles, for instance, with the engraved guilloché decoration overlain by negative painting. Archeological excavations have found examples of non-local pottery from this period as well. Made from non-local clay sources, the pieces have designs or vessel forms atypical for local wares. At the Madisonville site was found a head pot similar to those produced in the Central Mississippi Valley by the peoples of the Middle Mississippian Parkin and Nodena phases. Archaeologists suggest that the change in pottery styles was a result of increased contact with the Mississippian cultures to the south and west of the Fort Ancient peoples. Tools The Fort Ancient peoples made tools from a variety of materials, including stone, bone, horn, shells and antlers; stone