Drawing Pretty Pictures of Broken Pots

The single most ubiquitous artifact type for archaeologists working on most time periods is ceramics. The wonders of chemistry and physics have resulted in a materiel that once produced is nigh well indestructible. Ceramics can be used to produce all sorts of different objects from electrical insulators to building materials like roof tiles and pipes, but the form we find most frequently is pottery. Pottery vessels are used for carrying liquids, storing dry goods, cooking, even as burial repositories. And they break with astounding frequency, and thousands of years later, the pieces are still around, sometimes even in the exact same condition they were the day the pot was dropped. Archaeologists rarely find intact pots – unless we’re excavating tombs, when people would intentionally place whole pots, perhaps filled with some sort of mortuary offerings or with the remains of a funeral feast, with the body of the deceased. But most of the time what we find are sherds… the detritus of pots broken during daily use or after they were discarded for other reasons.

Now the uses of pottery to archaeologists can’t begin to be overstated. Pots can allow us to study social organization, political developments, economic strategies, exchange of ideas, movement of populations, and any number of other topics. Because of the ways in which new styles are adopted, developed, discarded and replaced, pottery can be used for establishing relative, or even absolute, dates. A lot of these things though, require us to know what the pots looked like, not just cataloging the dirty sherds that come out of the ground. So, what does an archaeologist do with all these thousands of pot sherds?!

Well, first we wash them! But after that, we count them and we record them. Recording a pot sherd usually just involves determining what kind of clay it was made from and how it was finished and fired – different wares are made of different clays, that are treated in different fashions – think of the difference between fine china and earthenware. However, if a sherd has some sort of decoration, or if its part of a pot that is recognizable, we call it “diagnostic.” This is sort of like being a symptom that lets you diagnose the disease. Well, a diagnostic sherd lets us diagnose something about the pot – what shape the pot was, what kind of decoration it had, or maybe whether it was made a special way.

Diagnostic sherds receive special treatment. We carefully measure them, record details about the fabric (the clay and other materials the pot was made from), the finish (firing methods, burnishing, slips, glazes, painted, inciside, or relief decoration, etc.), and what part of the vessel they were. Sometimes from all of this information we’re ale to tell exactly what kind of pot the sherd came from! And then the sherds are drawn and photographed. As a pottery analyst, drawing pottery is a skill I had to learn, and trust me, I have no innate artistic talent! I’ve been doing it for long enough now that my drawings are acceptable, but there are many (if not most) archaeological illustrators out there who put my drawings to shame. Still, I do all right, and I thought I’d give you guys a little look at how I spend some of my days…

To start, I have to get all of the tools of my trade. Here you can see some nice heavy tracing paper, taped down to a smooth, flat table, over a sheet of graph paper. This way the graph paper can be reused, and the lines don’t have to be removed when the drawings are scanned into Adobe Illustrator and inked, but the grid is still there to help with the drawing process. I also have an architect’s ruler, a triangle, a profile gauge, a set of calipers, a rim gauge, my favorite mechanical pencil, and the pot sherd that I’m going to draw with its ID tag.

Here’s a clearer shot of the sherd in question as well as some of my earlier drawings so you can see what the goal is. This particular sherd is the rim, and a significant chunk of the profile of the body of a hemispherical bowl, a very common form in the bronze age on Cyprus. Specifically, this sherd is a variety of Red Polished ware local to the Pafos region in the SW of the island, dating to the Early or Middle Bronze Age.

The trick to being able to reconstruct a vessel from a single sherd is being able to orient the sherd correctly so you can figure out what the profile of the sherd would have looked like. Normally this requires having a rim, or at least a significant part of it. IF the piece of rim is to small, you can’t tell what angle to hold the pot at. In this picture I’m holding the sherd at close the correct angle. If a piece of pottery is well-made, then the rim should be even, and if the rim is even then if you hold the sherd so the rim is flat, you’ve figured out the correct angle that the sherd should be at! Another way to do it is to place the sherd on the table rim-edge down. You lean the sherd back and forth until you find the angle where no light is passing under the sherd – this means you’ve found the correct angle where the rim in lying flat against the table. Once you have this angle there are a couple important measurements you can take.

First, you can use a rim guage to figure out what the diameter of your pot’s rim was. Here you can see me using the rim guage, holding the sherd so no light passes under the rim (i.e., the rim is flat, and I’m holding the sherd at the correct angle). I slide the sherd in and out on the gauge until I find a rim diameter that matches the curve of the rim on my sherd. Voila! I know how big around my pot’s rim was! In this case, 14 cm…

Using this rim measurement, I’m able to sketch in this T. Basically the cross bar is the rim, and the upright is just the axis of reflection (i.e. the other side of the line will be a mirror image of whatever I’ve drawn). By aligning my sherd at the correct angle again, this time on the T, I’ll be able to measure how high the sherd is and how far in it reaches. I’ll do this using the graph paper underneath and the architect’s triangle:

These measurements allow me to mark the bottom of the sherd on my drawing. The trick now is figuring out the curve between the edge of the rim and this bottom point. And the way we do that is with the profil gauge. These are also tools used by carpenters and other craftsmen. The metal pins push in easily, but remain in place horizontally. By pressing the gauge up against any object (even your face, but its kind of uncomfortable), when the pins push in you get the curve of the profile of the object you’re measuring. Good profile gauges also have built in rulers, allowing you to measure the distance between different points in your curve, which is great if its a complicated curve (like your face). In this case, though, I’ve got a pretty simple curve, so I can just put my sherd on the table and press the gauge down, being careful to press the guage in at an angle that would point towards the imaginary middle of the pot.

This last picture actual skipped a step (whoops!). One I’ve gotten the profile of the pot in the gauge, I line that profile up with the edge of the rim on my T and with the bottom of the sherd which I marked after measuring with the triangle. This lets me draw the curve of the outside of the pot. For the interior curve I use the calipers to measure the thickness of the sherd at various points. I marke these distances in on the drawing, and then basically connect the dots: instant inner surface!

Now, using the grid paper as a guide, I draw in the mirror image of the profile on the other side. Little conventions like a broken rim line tells us that the rim is incomplete, and extension lines at the base of the sherd show the sherd is broken here and would be expected to continue in a certain direction. Then I label the drawing with the project abbreviation and excavation year, the trench and context numbers where the sherd was excavated, and my initials and the date the drawing was completed. Done!


One thought on “Drawing Pretty Pictures of Broken Pots

  1. It’s a process I always wondered about–how you would record accurately the details of a partial object and then extrapolate to a total object.

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