◊ Dear Microburins,
The extraordinary James Dilley @ancientcraftUK is working through multi-period replica assemblages for my lithics training workshops this year, and beyond. The workshops deal with the archaeological aspects of lithic assemblages—chronological trends, research questions, technology, typology, identification, function, field archaeology best practices, analysis, recording and interpretation. The teaching materials also include other material culture associations, such as ceramics courtesy of Graham Taylor @pottedhistory and Bronze Age artefacts by Neil Burridge.
Selecting the correct pottery and lithic types to illustrate typological and material culture changes through prehistory. The pottery here is early Neolithic Grimston Ware from Yorkshire (c. 3800-3500 BC) and Early Mesolithic microlith flints from Star Carr (c. 8770-8460 BC).
What’s particularly useful in the expert knapping that James is undertaking is that each of the four period-based assemblages will be near complete, or at least a representative sample of coherent reduction sequences and artefact manufacture. James is also going to intentionally break some pieces.
The Reality of Bias
In reality, in the field:
- Recovered lithics often represent multi-period mixtures where places have been visited and revisited over time (persistent places);
- There is variation in past human activity in space and time, from the selection and testing/rejection of raw materials, stages of reduction and tool manufacture, selective or even random events in the movement, breakage, discard, use and re-use, caching of raw materials and artefacts—we call this the chaîne opératoire;
- There are biases in survival, including disturbed contexts, where lithics are residual (not in original context) because of later activity or natural events, including agriculture and movement in sediments;
- There are biases in archaeological recovery, whether intentional sampling or uncontrollable factors related to the nature of the recovery techniques employed—and of course in the ability to identify a lithic and human interpretation, always subjective to a degree, of assemblages.
artisans at large
- Ancient Craft website (James) »
- Potted History website (Graham) »
- Bronze Age Craft website (Neil) »
- TimeVista Archaeology (my formal website) »
♦ Spence
I’m largely self-taught and results-driven when it comes to photographing lithics. I’ve experimented with black backgrounds and lighting configurations with some success. However, depth of field and pronounced shadowing for the more substantial artefacts have provided some challenges. Inevitably, a significant amount of work in image enhancement software is also needed, plus the addition of graphical scales (I use Corel because Adobe is too expensive). There can also be problems with darker coloured materials and especially the edges against a rather brutal black background. The results have been good, I think, but time-consuming. 
What I now find is far more efficient and consistent is using an acrylic frosted block, the type you see in museums or retail displays. In diffused natural daylight the block lets sufficient light permeate around the base of an artefact to suppress excessive shadows – the object almost seems to float in a milky ether – and allows for a small enough aperture (high f/stop number) to counter blurring within the frame, or between the top of an object and the scale, such as with deep objects like cores, items with heavy curvature or a deep arête. Lighting can be tuned by raising the block on a clear acrylic stand or placing foil or white card underneath – much cheaper than using a lightbox (not very transportable) or augmenting with artificial lighting. By using a good quality photographic scale I’ve also avoided the need to overlay digital scale images, although this is easy enough to do. And if an object needs support, I actually find that soft silicone earplugs (like bluetack but colourless) work fine.
Having a colour-correction scale has helped to maintain consistent hue/chroma results and I can, pretty much, adjust all images in a sequence using batch mode in photo/paintshop software, including corrections for barrel distortion (depends on your lens). The results feel good enough for archive/grey lit reports and need little extra work for publication-quality, as and when that becomes necessary. You can also combine objects, matched to scale, in a single merged image. You can’t really beat a good lithics line drawing but these remain open to the biases of interpretation – the eye of the penholder – and completeness in terms of what is included, excluded or emphasised. Drawing is subjective.
microburin 