Experimental approaches to ceramic technology: Dung tempering and clay mixing

By Carlotta Gardner, Associate Editor for Archaeological Ceramics

It is largely accepted today that the study of ceramic technology is key to exploring important social and economic questions about the past as well as dealing with issues of provenance. With this, we see the discussion of ceramic technology through the use of multiple techniques and theoretical frameworks regularly in publications on material from across the world and from all time periods. More recently we have seen an important step towards developing our understanding of how we can identify steps in the chaîne opératoire and specifically in paste preparation methods. 

A heap of dung! (Copyright Anne Burgess and licensed for reuse under this Creative Commons Licence)

There are/were many different ways potters prepared their pastes prior to use. These include refining through methods like sieving and levigation; the addition of aplastic material—from grass, dung, and sand to grog, slag, and bark ash—as temper; and the mixing of different clays. Using a variety of scientific techniques, often in combination, we are able to identify a number of these adaptations of the raw materials. There are however a number of examples which are still more challenging to identify. Two of these have become the focus of recently published experimental projects: the addition of dung temper and clay mixing. 

Dung tempering is well accounted for in the ethnographic literature and many archaeological examples have been suggested. However, it is relatively challenging to provide conclusive evidence of this. Amicone et al.(2021) in their wonderfully titled paper “Seeing shit: assessing the visibility of dung tempering in ancient pottery using an experimental approach”, explore through experimental means how we might be able to identify this process more confidently through a variety of scientific techniques. Whilst the paper concludes that the identification of dung is still not straightforward, due to a range of different factors (including the dung itself and firing conditions), it makes promising steps to being able to confidently identify dung tempering. 

Intentional clay tempering is another process widely used and described in ethnographic accounts. It is also a challenging process to identify in archaeological material for a number of reasons including the presence of naturally variegated clays. It is an important issue when considering matters such as provenance and it arises in a number of research papers and was also the topic of the most recent microscope session at CPG 2021. Ho et al. (2021) designed and implemented a strong experimental approach to this subject, mixing a range of clays in different ways to study the material under the polarising microscope. In addition, they sampled naturally variegated clay for comparative purposes. A series of textural features were identified as markers of this process however, like Amicone et al. (2021), the issue of identifying clay mixing was complex and the authors state further work is needed. 

Both papers show the complexity of identifying different stages involved in the paste preparation for archaeological ceramics. Equally they show the need for experimental approaches to these kinds of unresolved problems in archaeological ceramics. Experimental work can be time consuming, and by all accounts rather smelly when dealing with material like dung, but incredibly rewarding - developing our understaning and ability to identify specific processes but also, I hope, our own experience of handling materials and understanding the motivation behind the use of these materials too. 

I highly recommend checking both papers out!

Amicone, S., Morandi, L.F., and Gur-Arieh S. 2021. ‘Seeing shit’: assessing the visibility of dung tempering in ancient pottery using an experimental approach. Environmental Archaeology, 26.4. 

Ho, J.W.I. and Quinn, P.S. 2021. Intentional clay-mixing in the production of traditional and ancient ceramics and its identification in thin section. Journal of Archaeological Science: Reports, 37.