Guest blog: New ways archaeologists ‘dig out’ answers

By: Victoria Nagy, MSc

After spending a field season conducting consultant archaeological field work in Ontario, I wanted to work in a research facility, an environment I enjoyed during my Masters studies. Therefore, I was excited to join the staff at Sustainable Archaeology: Western University. During my past undergraduate and graduate studies I had been exposed to digital archaeology and database development but I had never been able to directly apply those skills.

I was fascinated by the shear potential for research at Sustainable Archaeology since I was first introduced to the facility back in October 2015. As an archaeologist with a background in scientific applications, I was especially interested in its scope and equipment. Research facilities such as Sustainable Archaeology are extremely rare in Canadian archaeology, its existence and continuing innovation fill a scientific void in Ontario archaeology. Sustainable Archaeology: Western University and Sustainable Archaeology: McMaster University showcase how Ontario values archaeological research and will focus on scientific applications to further understand Ontario’s rich heritage.

Hilary Kiazyk, a part-time employee at SA: Western, using the Artec Spider to scan a mammoth tooth (a part of a collection from the Museum of Ontario Archaeology) (Feb. 29, 2016).

My first week at SA I familiarised myself with two of our 3D scanning technologies: the white light scanner and the mobile Artec Spider scanner (blue light scanner). I created a 3D model of a projectile point using the Artec Spider and tried my hand at using a white light scanner with a Historic smoking pipe. The Artec Spider blue light scanner proved to be my favourite piece of equipment in the imaging lab. The speed at which it captured images greatly shorted the imaging process. Also, the editing functions were easier to use and more comprehensive. I definitely enjoyed forming an opinion about these incredible pieces of equipment.

I was also able to print a previously rendered 3D model to better understand the 3D printing process. I learned how key texture editing is to the printing process. Since SA’s 3D printer is a powder printer that applies texture (colour in layman’s terms) during the printing process, editing the texture before printing to obtain the most lifelike texture (and then ensuring the texture seen on a computer monitor is adjusted to reflect the real texture) is essential to creating a lifelike replica. Through their work with 3D printing, SA is creating a new collection of archaeological mimics that can be used for display, study or function.

The applications of 3D scanning and printing are endless. Two replicas of the famed Ötzi were recently produced at Materialise in Leuven, Belgium as a dual effort by the DNA Learning Center and the South Tyrol Museum of Archaeology. The team who replicated Ötzi via 3D printing used a CT scanner to generate the 3D model of Ötzi, much like the Micro CT scanner SA owns and operates. The Micro CT scanner at SA is primarily used to understand the internal structures of artifacts. Internal structures can convey to archaeologists how artifacts were made, what materials were used, and reveal any unseen processes. Using a Micro CT scanner would have brought another dimension to my past research studying the newly introduced rehydroxylation (RHX) dating technique. I was only able to conduct Thermogravimetric Analysis (TGA), which analyses materials’ response to intense heat (Nagy 2015). Access to a Micro CT scanner would have provided me with a much more accurate examination of the internal construction of my samples. The fact that this equipment is available to Western students, and other researchers is so important for future research in Ontario and the wider academic community.

Staff of Materialise and Gary Staab (the expert paleoartist behind the Ötzi replicas - second from the left) (Cold Spring Harbour Laboratory 2016).

As my time at Sustainable Archaeology continues I am constantly amazed at this facility and the potential it represents for the archaeological community in Ontario. The non-destructive analysis conducted here is necessary for the archaeological research of the future. Sustainable Archaeology is providing the next generation of archaeologists with the tools they need to conduct high caliber research. Sustainable Archaeology has facilitated new processes for archaeologists to ‘dig out’ conclusions. I look forward to my time here and the research in the immediate future that results directly from Sustainable Archaeology’s efforts.


References

Cold Spring Harbour Laboratory (2016). The making of Otzi the Iceman. https://www.dnalc.org/programs/otzi.html?utm_source=ALL+CUSTOMERS&utm_campaign=9ea4241666-MED_Otzi&utm_medium=email&utm_term=0_7544445bcb-9ea4241666-63081529&goal=0_7544445bcb-9ea4241666-63081529.

Nagy, V. 2015. A methodological study of a simplified rehydroxylation dating procedure (Unpublished Master’s thesis). Durham University, Durham, UK.


Author biography

Victoria Nagy is a new addition to Sustainable Archaeology: Western University. Victoria graduated in 2015 with Distinction from Durham University with a Master of Science in Archaeological Science. In 2013, she graduated with Distinction from Wilfrid Laurier University with a Bachelor of Arts (Honours) in Near Eastern and Classical Archaeology. Victoria has conducted archaeological field work in Jordan, the United Kingdom, as well as northern and southern Ontario. She has joined Sustainable Archaeology as a Data Entry Assistant to aid existing staff with database development. This week is her fourth week with SA: Western.

Tracking our Progress

One of the reasons that we love sharing and updating Sustainable Archaeology's progress on our blog is the opportunity to look back at how far we have come - literally from the ground up! In March of 2011, our Ancient Images Laboratory was just concrete, an idea of what could be. Now, in March of 2014, we have a fully outfitted and functioning space that features our micro-CT scanner, digital x-ray, artifact photography stations, and 3D printer.

3D Printing - testing size and colour

We have been running the 3D printer through its paces, working with scaling the printed objects, and with different processes and products for post-printing infiltration. 

Our test object was a small red projectile point. The point was first scanned in 2012 by the Sustainable Archaeology Animation Unit using the macro white light scanner.  

The untextured (left) and textured (right) scans of the point

In order to see how the printer was handling the detail captured in the original scans of the projectile point, we decided to print not only an original sized replica, but also one that was 2x larger, and one that was 3x larger.

Print in progress in the build bed

By scaling the model, we are able to better see with the naked eye the detail that was captured in the scan. Depending on the end user need, printing scaled versions of the scanned object may prove beneficial - for example, if there is detail not easily seen by the naked eye, or where we wish to isolate and print one segment of the object at a larger size in order to examine a specific feature of the original. For example, with our print, we are able to better see each flake scar on the point by examining the larger model, and could use the larger model to take measurements (converting to account for the size difference).

Scaled 3D prints (left to right): 3x larger; 2x larger; original size

Back side of the three printed points

In addition to testing scale, we were interested in testing how different infiltration products and methods affect the end product. We printed several copies of the point at its original size, and used the 3D Systems infiltrant Z-bond, as well as Paraloid B-72 resin, and the salt water infiltration we had previously used for our first print test.

Infiltrating the prints (left to right): Z-bond infiltrant; Paraloid B-72; salt water

Back of prints with different infiltrants (left to right): Z-bond; Paraloid B-72; salt water

As you can see from the images, the print infiltrated with the Z-bond demonstrates the most robust colour. The Paraloid resin offers a significant improvement over the salt water, and we plan to explore its use further, using different concentrations of the acrylic resin in acetone. As with scale, the end user need will help determine what infiltration product will be used with a print - for example if the user is interested in a print as a replication, or whether they simply wish to have a physical copy of the scanned object to handle and examine.

Comparison of the original artifact (left) with the Paraloid (center) and Z-bond (right) infiltrants

3D printer training and our first test print

On February 6th and 7th, we received training for our 3D Systems ProJet 660Pro printer. Training included not only how to set up and complete a print using the software, but also essential steps such as the cleaning  of the machine that is required after the conclusion of each print. 

After completing the necessary setup, calibration, and print head alignment, we performed our first test print, using a scan of a small bone comb that had been completed using Sustainable Archaeology's white light 3D digitizers. To test the process of positioning objects in the build envelope using the software, we printed three copies of the same object.

Printing in progress.

After a print is completed, the parts must be carefully excavated from the excess powder in the build envelope. The parts are quite delicate prior to any post-processing treatment, and can easily be broken during removal from the powder. Our objects were particularly delicate, as to maximize our training time, we did not allow for the usual one to two hours of drying time generally recommended between the conclusion of the printing process and the start of post-processing.

Excavating the prints

For our first test, we experimented with one of the available post-processing techniques, which is infiltration using a solution of Epsom salts and water. We plan to experiment further in the coming weeks to determine what scanning procedures produce the best files for printing, and to determine what post-processing techniques will produce the best colour replication. 

Front and back views of the completed print

The final print (right) and the original object

January Arrivals at SA

Happy new year to our blog readers! We've had a busy January so far, welcoming two new arrivals to the facility: our (much anticipated!) 3D printer, and our new artifact cabinets. 

 

The 3D printer is a 3D Systems ProJet 660Pro from vendor Progressive Educational Systems Inc. The ProJet 660 uses a composite powder rather than plastic for its build material, and has the capability to create replication-quality pieces in full colour. Stay tuned for our inaugural "first print" post!

Interior view of the printer

In addition to the printer we received our Delta and Rousseau cabinets from Spacesaver Solutions Inc. The cabinets will be used to house special or fragile artifacts.