EXARC Extracts 2026/2

In the second episode of EXARC Extracts in 2026, Matilda Siebrecht talks you through the content of EXARC Journal 2026/2.

This issue includes six reviewed articles and seven mixed matters articles. All the articles are open access to allow for free exchange of information and further development of our knowledge of the past.

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Transcript

Hello and welcome to EXARC Extracts, where we take a tour through the latest issue of the EXARC Journal and highlight some of the fascinating experimental archaeology and reconstruction research being published by both EXARC members, but also those from much further afield. My name is Matilda Siebrecht. In this episode, we're going to be looking at the six reviewed articles from the second issue of 2026. As always, the Journal covers an impressive range of topics, from Roman mystery objects and neolithic stone axes to textile production, Roman laundry practices, obsidian blades, and even the science behind miraculous blood relics.  

So let's begin with actually one of archaeology's most enduring mysteries. The very first article that we have here is written by Greg Lamb and it is entitled A Functional Reassessment of Roman Dodecahedra as Tools for Forming Standardised Wax Objects. For those who are unaware, Roman Dodecahedra, also known as Gallo-Roman Dodecahedra, are some of the most puzzling artefacts that have ever been recovered from the Roman world. They're generally hollow bronze objects, usually dating between the second and fourth centuries AD, they have 12 pentagonal faces, circular holes of varying sizes and little knobs on every corner.

There's been more than a hundred examples found, especially in the northwestern provinces of the Roman Empire, but no one's ever actually found a contemporary Roman description explaining what they were for. And as you can imagine, this means that people have gone wild with theories. I really love these kinds of objects personally, these sort of prehistoric to historic mystery objects that we have no idea what they were used for, because it provides all sorts of interesting theoretical experimentation.

There's been all kinds of interpretations made, from surveying instruments, gaming devices, ritual objects, even knitting tools, which many people are more familiar with now. In this article the author approaches the problem through experimental archaeology, of course. And rather than beginning with pure speculation and symbolism, he asked a very practical question, which is, what could you actually do with this shape rather than going the knitting tool route, which is how it was approached before.

The author uses 3D printed replicas and experimentally prepared wax mixtures to test whether the Dodecahedra could have functioned as tools for producing standardised wax objects. For example, what's known as bulla, which is the lumps of wax used to seal cards or documents or containers. Interestingly enough, the experiments produced some surprisingly convincing results. There's some very interesting images showing examples of exactly how they were used, by the way. Of course, this is an audio format podcast, but if you want to find out more, please do go and check out the article to see pictures of the replica and the little bulla that it produced.

When softened wax was pressed into the dodecahedron, the geometry kind of naturally created this very consistent shape with a very controlled thickness, and a little raised central boss sort of suitable for receiving a seal impression. The knobs actually acted as built-in spaces, which was quite interesting, preventing over-compression, different hole sizes accommodated different cord thicknesses, and larger holes even allowed fingers to reach inside and pushed the finish wax object out without damaging it, for example.

What's interesting is that these experiments, of course, one of the most important parts of experiments in archaeology is repeatability. And indeed this tool could create repeatable results as well. Of course, handmade wax seals could certainly be produced without it, but the dodecahedron kind of regularised the process and it produced objects with a very standardised appearance.

So that is the article's kind of central argument. They talk in a lot of detail about the wax mixtures that he used, the different temperatures that he used, all of the different aspects of the experiment that could have affected the experiment itself and the results, which is very interesting. They talk about revised method, functional observations, and indeed this sort of repeatability and thickness consistency. The author argues that the value of the dodecahedron may not have been that it made sealing possible, but it could have formalised and standardised that as an administrative practice, which, everyone who does anything to do with Romans probably knows that visual order and official presentation matters a lot and efficiency and standardisation seems to have been a big part of Roman society.

Therefore a tool like this, which created recognisable and consistent wax forms, could have considerable value. What's important to note is that this study doesn't claim to have solved the mystery once and for all, but it does demonstrate very interestingly that wax forming is plausible. It also compares with kind of seal box dimensions and other things like that. So it adds in extra aspects of the workshops that were undertaken and extra aspects of the Roman cultural context as well. It does demonstrate its possibility and also that some previously puzzling design features actually could make sense when viewed through this lens. So it's a reminder that experimental archaeology can really sometimes reveal practical possibilities that are difficult to see if we just look at it through typological analysis alone. 

The next article we have is entitled Life of a Stone Axe. Chaîne opératoire of Neolithic Polished Stone Tools Based on an Archaeological Experiment. A view at the second life of polished tools from Czechia. Again, as always, please excuse any mispronunciations that I make. The authors of this article are Radomír Tichý, Iva Dohnálková, Karel Kučírek, Aleš Panáček and Petr Zítka from various institutions based in the Czech Republic. 

This article represents a very different kind of experiment. It's not one that's measured in hours or even days, but in years. The authors set out to reproduce the entire lifecycle, or chaîne opératoire of neolithic stone tools. It took eight years of detailed documentation and experiments. They even mention in the abstract that just the drilling alone was more than 2,500 hours of work. So a really long-term experiment here.

They weren't simply trying to make a replica of the axe. They were trying to understand every stage of the tool's life. So raw material acquisition, manufacture, use, breakage, repair, reuse, and interestingly, eventual transformation into something completely different. This investment really allowed the researchers to explore something that's often quite difficult to reconstruct archaeologically, which is the second life of stone tools.

Generally, when archaeologists find polished stone axes or adzes or other tools, they're quite often seeing objects that of course, at the end of their life, the end of a very long and complicated biography. So what you see as the end result might not necessarily be what it was originally intended for.

Many of them might have been reshaped or repaired or reworked or repurposed multiple times. By recreating these processes experimentally, researchers are able to gain insight into, for example, how usewear patterns develop, how tools change through repeated cycles of use and modifications.

That's also what this study did, which is really fascinating. They go into a lot of detail about the methodology used, previous experiments that have tried to consider longer term processes and chaîne opératoires as well. An overview, of course, of the polished stone tools in eastern Bohemia, and a description and assessment of the experiments within the context of the polished stone tool finds.

By recreating the processes experimentally, the researchers were able to gain some really interesting insights, especially one that it challenges potentially simplistic ideas of neolithic tools as just static objects. This is something that is being quite often talked about in a lot of different articles recently, actually.

This article goes into a lot of detail about the exact experiments that were done, by the way. I won't go through all of them, but if you want to see all of the different kinds of experiments, they have a very detailed table just here talking about drilling experiments. They talk about the hole depth, the drill length, abrasive material, the time of drilling, the weight, the drill number, what was drilled in an hour in terms of millimetres, the drill loss in terms of millimetres, and any other notes. They have that for all of their experiments that they did. So I would highly recommend checking it out if you want to get a lot of data from this. At the end, they show that these artefacts actually could have been quite dynamic possessions. The value of them encouraged that repeated repair and reuse. They weren't just sort of a one-off thing and a broken axe also wasn't necessarily just discarded. It could become a smaller tool. It could be reshaped into another implement, or it could continue functioning as an axe, but just in a modified form, which I think is really fascinating. Also what's really great about this article is it shows how long-term experimental programmes can really interestingly reveal aspects of prehistoric technology that shorter experiments might just miss, which of course is fair enough, right? There's restrictions in time in terms of how you can do. 

If you're interested in finding out more long-term projects, especially about neolithic material culture, I would highly recommend checking out the Putting life into Neolithic Houses project of which EXARC was a partner. The project has finished now, we had our final symposium back in March. All of the talks and the recordings from that event are now up and published on the EXARC YouTube channel. So do make sure to go and check that out, and check out the playlist, Putting life into Late Neolithic Houses on the EXARC YouTube channel if you want to find out more about other kinds of long-term experiments like this.

The next article that we have has a very ‘clickbaity’ title I must say. It's written by Luigi Garlaschelli and Giacomo Torzo and it is entitled Mysteriously Liquefying Blood Relics in Italy. I mean, if that doesn't get you in, I dunno what will! This topic is a really fascinating one. It's not just experimental archaeology. They talk about science and religion as well as experimental reconstruction. 

So a little bit of background. There are several mediaeval relics in Italy, which are famous for what's sort of considered a miracle, with substances believed to be blood were periodically changed from a solid state into a liquid state. The most famous example is associated with Saint Januarius in Naples, but there's similar relics existing elsewhere. In this article, the authors examine this phenomena from an experimental perspective. I must make the point that the goal in this is not to challenge religious beliefs or the miraculous nature of it, but just to investigate, you know, alternative potentials. For example, to see whether perhaps natural explanations could account for that observed behaviour. There's also some really fascinating pictures of these objects. So I would really highly recommend checking out this article to see it in detail. 

The authors explore a couple of different possibilities. The first is known as thixotropy, which is a property that's found in some materials that allows them to become fluid when shaken or disturbed. They discuss a little bit about that as a case. Then the second theory that they suggest is that relics perhaps consist of low melting point substances that then liquefy when temperatures rise. There's a lot of detail that goes into the different aspects that this could entail. Talking about the pros and the cons of the different theories, they talk about things like ease of preparation, stability over time, details of liquification, historical plausibility. They talk about different fat types. They talk about potential materials. They go into a lot of detail about it. They talk about dyes that could be used to make it look like blood and how these would react in terms of the preparation. Of course, they don't stop at theory. They do also experimentally reproduce some of these relic-like substances and they demonstrate that materials with these characteristics could indeed behave in ways remarkably similar to the more famous relics. Some good candidates that they mention is coconut oil dyed with bitumen of Judea or clarified butter dyed with Alkanna extract or clarified butter, or possibly red palm oil with different dyes used.

They, of course, accept that further data is needed. But it's a really fascinating article and what makes the article especially interesting is that it still follows a classic experimental archaeology approach. So it reconstructs the possible historical materials. It tests their behaviour under realistic conditions. And it just goes to show how, whether one approaches this topic from a scientific, a historical, a religious perspective, this study really provides a fascinating example of how experimental methods can be applied to questions that are far beyond traditional artefact reconstruction. And I find that just so fascinating, always about the EXARC Journal. I mean, in these first three papers, we've already seen three very clear experimental projects, but they're all very different in the approaches that they take and the goals that they have. 

Which takes us on to the next article entitled Slicing into the Past. Experimental Use of Obsidian Prismatic Blades and Analysis of Modern Botanical Residues. This is written by Éloi Bérubé and Shanti Morell-Hart, based in Canada and the US. This article takes us to Mesoamerica, where we focus on one of the sharpest tools produced. I can account for this, I have had bloody fingers when trying to knap obsidian blades. The researchers wanted to understand how microscopic plant residues become deposited on obsidian tools and how these residues might survive for archaeologists to discover.

I always find these types of studies really fascinating because they can show that not only can we use experimental archaeology to actually understand past cultures, but we can also use it to try and understand how the results and the data that we find as archaeologists is affected by post-depositional processes. So how things that happen in the ground, how all of these different things affect what we see as archaeologists and therefore how we interpret the past. In order to investigate this the authors produced 20 obsidian prismatic blades from a fresh core, and they used them to process a range of plants that are commonly found in archaeological contexts. This included maize and sweet potatoes and squash and manioc and hardwood. Then after their use, the blades were subjected to a very detailed micro-botanical analysis. You can see some beautiful pictures of the starch grains if you read the article. They were looking for then indeed starch grains and phytoliths, so the tiny, tiny plant remains that then provide us clues about ancient food preparation and plant processing. 

This article also documents the experiences of the experimental participants as well, which is also extremely important. They have a lot of participant observations, because at the end of the day, archaeological interpretation is pretty subjective. So it's always interesting to learn about the experiences and the observations of the people who are actually conducting the experiments as well. Indeed modern users quickly discovered how incredibly sharp obsidian blades are. So, cuts were very common. Blades also broke a lot during use. And because of this, participants really had to adapt their grip styles and their handling techniques as they became more experienced in this particular type of activity. These observations obviously provide really valuable insights into how ancient users of these blades may also have interacted with similar tools. There's a lot of details about the micro-botanical analyses, a lot of detailed tables and overviews of the results for each of the different plant materials.

This study suggests that the visibility of plant residues on archaeological tools depends not so much on the sequences of activities performed, but more actually on the kind of inherent properties of particular plants and the residues that they produce. So in other words, some plants just leave more archaeologically visible traces than others, which I think makes sense, as a usewear analyst myself. Again, this article really demonstrates the value of combining different types of methodological approach related to experimental archaeology. So this one includes experimental archaeology, usewear studies and micro-botanical analysis in order to better understand both culinary practises and food processing technologies, but also the preservation of traces that we could then see in the archaeological record.

Our penultimate article is by Kayleigh Saunderson, Anna Zimmermann and Karina Grömer and it is entitled A New Tablet Weaving Technique from Bronze Age Hallstatt. Textile archaeology has really benefited enormously from the remarkable preservation conditions at Hallstatt in Austria. If you haven't heard of it, do look it up. It's really fantastic. We have quite a few of our EXARC members who are working on textiles from this region and also from similar regions, so the salt mines in other parts of Germany as well and other parts of Austria. I would really recommend having a look and doing a little search in the EXARC Journal because I believe there are a couple of other articles which deal with similar topics.

The researchers here examined a very particular textile,  known as HallTex390 B, which was recovered from the late Bronze Age Tuschwerk mine. At first glance the textile appears fairly straightforward. They have some beautiful pictures in here. It's really nicely woven. It's a really interesting pattern. There's sort of two woven fabrics, which are then connected with kind of a narrow ribbon. But actually on closer examination, the article tells us, there's something far more interesting going on. The ribbon part actually combines features that are associated with both tablet weaving and warp-faced tabby weaving. It creates this structure that apparently does not match any previously documented technique. So the result that you have is kind of a distinctive, ribbed pattern, almost with mirrored kind of symmetry of the pattern and sort of alternating structural elements.

So in order to understand how it was made, the researchers wanted to try and reconstruct the textile experimentally through a series of different trials, which they discuss in a lot of detail. They developed a plausible weaving technique capable of producing the observed structure. The experiments that they conducted revealed not only how the ribbon may have been manufactured, but also showed the technical sophistication of the people making these objects, so these Bronze Age textile producers. 

Again, one of the enduring strengths of experimental archaeology is that it allows us to move simply from describing unusual objects - so similar to the first article here about the dodecahedra - to actually understanding the skills and decisions required, not just to use them, but also to create them in this case. In this particular case the reconstruction process uncovered evidence for a previously undocumented weaving method and really expanded the understanding of prehistoric textile technology. A wonderful example of how even a tiny little fragment of cloth can contain real evidence for sort of innovation and specialised craft knowledge. So really interesting, beautiful pictures as well, by the way. I can't describe them in detail, so please do go and check that one out. Also, if you're interested in textiles research, I would encourage you to join our Textiles Working Group, which is very active and can be found on the Discord server.

Our final article is also about textiles. This one is entitled Reconstructing Textile Cleaning in the Ancient Roman Fullonicae, written by Kaira Shlipak. This one tackles one of the most famous aspects, apparently, of Roman daily life, which are the Roman laundries, otherwise known as Fullonicae. I apologise sincerely to all of the Roman archaeologists listening in who are probably screaming at me from their headphones. I am, as can be very clearly just seen, not a Roman archaeologist, I'm afraid. I'm not sure how Latin pronunciations are properly done. 

These Roman laundries are apparently quite well known for their use of urine as a cleaning agent. Modern audiences often find that detail kind of amusing or shocking. But the question that we want to know is just how effective was urine and this author decided to find out. The article goes into a lot of detail about different kinds of approaches that were used.

There were three treatments that were compared. So first of all, there were some white woollen textiles, and they were stained with different substances to mimic everyday Roman life, ancient Roman dirt and spillages. So there was olive oil, soil, wine, and tomato-based sauces. After all of the stains had set, the samples then underwent a washing process, which is modelled on evidence from these different sort of Roman Fullonicae workshops. They talk about that at the beginning of the article and a little bit about the cultural context of that. 

Then three treatments were compared. The author used stale urine, dilated with water, modern castile soap, and a control group that received no additional treatment. The results seem to be very striking actually. The urine solution performed comparably to the soap, and in some cases actually removed oil and dirt slightly more effectively. Both treatments, interestingly, apparently left the wool relatively soft and, interestingly, the urine-treated textiles apparently retained no detectable odour after drying, which I do find interesting. I quite like, by the way, one of the final paragraphs of the article, which talks a little bit about the personal experience of the experimenter, especially, I'm going to just read the last two sentences of the penultimate paragraph: “I sat on the floor rather than stood, used my hands coated in gloves rather than my bare feet and protected my face with a mask and goggles. There was only so much I was willing to subject myself to in order to replicate the experience of ancient Roman fullers”. I find that an excellent insight into the trials and tribulations that we as experimental archaeologists sometimes have to undergo. But it's a really fascinating result and the experiment provides a really interesting practical demonstration of why urine might have become such an important kind of industrial cleaning agent in the Roman world.

Rather than representing a bizarre or an unhygienic practice, it was actually quite a rational response. They looked at the chemical properties of ammonia potentially, and its effectiveness in removing grease and dirt from wool. So this is to end on just sort of the perfect example of the kind of study that experimental archaeology really does best, which is taking a very familiar historical claim and testing it out in practice.

That brings us to the end of the Reviewed articles. We then also have seven Mixed Matters articles. As always, these shorter contributions provide additional perspectives, so sort of smaller scale experiments, discoveries, and also reviews.

We have a conference review on The 7th CONEXP held October in 2025 in Liège (Belgium). The review is written by Martin Julio Garcia Natale and Cyrielle Mathias. 

We also have an interesting article, entitled 100 Bloomery Iron Smelts: Presenting the Data Web Linked Tables written by Darrell Markewitz and Neil Peterson.

We have a book review written by Anders Kiiehn Hansen on Forsøgets Fremtid – Fra Eksperiment til ny Arkæologisk Vide by Henriette Lyngstrøm and Camilla Fraas Rasmussen.

We have another conference review by Julia Heeb on the CIMA conference, held in Germany in March, 2026.

We have a small article called The Rolling Flange Hypothesis: A Mechanical Reinterpretation of Trilithon Block Movement at Baalbek, written by Anthony Scavo. 

And another article called Prehistoric Immersions - Living, Experimenting and Feeling the Prehistory by Pedro Lucas Salcedo and Teresa Fernández Azorín.

And finally and sadly, we have an obituary of Prof. Dr. Mamoun Fansa, who unfortunately passed away in April, 2026. And that is written by Julia Heeb.

That brings us to the end of our tour through the EXARC Journal, second issue of 2026. As always, it really showcases the incredible breadth of experimental archaeology, from reconstructing Roman administrative practices and textile technologies to investigating miraculous mediaeval relics, prehistoric stone tools, ancient food preparation, and even  Roman laundry techniques.

If you'd like to read any of these articles in full, you can find them available open access, completely free to read through the EXARC Journal, which can be found at www.exarc.net. If you would like to read more about what our EXARC members do, you can also check out the EXARC blog, which is found on the main EXARC website, which is www.exarc.org.

If you want to follow us along, please do follow us on all social media, subscribe to our newsletter, keep an eye on the news section. You'll see some really interesting events coming up as well.  We will be having our first live event in collaboration with the European archaeology days.

At the end of the month, we will also be having a live event hosted by our Live Interpretation Working Group on the concept of festivals as a form of archaeological interpretation. And of course, we have our Conference in November in Berlin, which is still open for registration, although the call for papers has now closed and we will be releasing the programme very, very shortly. So do keep an eye on our socials and newsletter and website for that. 

Thank you as always for listening to EXARC Extracts. If you enjoyed this episode, be sure to check out the rest of the EXARC show, and don't forget to check out the Journal and explore the latest research being published by EXARC. Until next time, thank you for listening.