One last look at the marbles

Just before the holidays, Mark the marble guy dropped by the NCMA to take one last look at the classical marble sculptures before he could hand over his reports and catalogue entries. Again we had to work in the dark galleries of the museum, but luckily we didn’t have to start as late as before… the sun sets much sooner in winter!

Assisted by Caroline “the Younger” (who was my intern in the spring), we reexamined the troublesome Hercules and just a few other sculptures with Mark’s nifty and very powerful flashlight, his new portable microscope and under ultraviolet lights. We also took photographs (UV and VIL/IRR) of details based on our earlier “night at the museum” sessions.  This should be the last examination of the marbles and the research on these works of art is pretty much completed… but the project continues with the study of other ancient objects from different Classical cultures and made from different materials.

UGA students visit the NCMA

Back on September 25, a group of students from the University of Georgia, Athens drove all the way up to Raleigh to visit the NC Museum of Art. The visit was part of Professor Mark Abbe’s course entitled Senior Seminar Greek and Roman Art: New Approaches and New Discoveries.

Discussing gallery design and object interpretation with students from the University of Georgia, Athens

Discussing gallery design and object interpretation with Mark Abbe’s students from the University of Georgia, Athens.

This study trip included a special curatorial tour of the Egyptian galleries, where I discussed the design of the galleries,  interpretation of objects and general curatorial work. Students also studied the Classical marble statues they had selected for a research paper due later this semester. I remained on hand to answer questions.

After a delicious lunch Neomonde (a must when Mark is in town), the visit continued in the NCMA’s Conservation lab, where Noelle chatted about paintings conservation, Perry demonstrated laser cleaning, and Corey and I talked about the Bacchus Conservation Project and objects conservation.

As always, it was a pleasure to spend the day with students who are interested in art and eager to learn about careers in the museum field.  (Clearly, the tour was deemed beneficial and interesting because I received a hand-written thank you card sent by snail mail! That was such a pleasant surprise.)

Pigment sampling

Now that we know there are traces of pigments on some of the Classical sculptures, it is time to take samples of all colours found on these objects. This task falls to Mark, who has to take minuscule samples of the pigments using the microscope or a head loupe to see them. Sampling will enable us to conduct further experiments (or have them conducted by a lab) to confirm the nature of the pigments with other scientific methods.

 

 

Seeing Red: VIL and IRR

In addition to UVF, we did Visible-Induced Luminescence (VIL) imaging on all the sculptures and, a couple of times, we did Infrared Reflectography (IRR) as well. In both cases, imaging is done in the near infrared range of the light spectrum. I will focus on VIL, but IRR is essentially the same (or so Mark tells me), but we used a red LED spotlight to illuminate the objects rather than the flashes. This makes for much more interesting photos and that’s why I’m briefly mentioning it here. (IRR is also regularly used in the study of paintings because it allows you to see preliminary sketches (underdrawings) underneath the layers of paint—that’s actually pretty cool.)

The setup for VIL is the same as UVF, but you mustn’t forget to change the camera and the filters on the flashes! Basically, we’d do UVF and VIL one after the other so the camera angles and distances remained the same for both series of photographs. Of course, before you do all that, you also have to take ambient light photographs of the sculpture. And to each series, you take one photo with the grey card… and another with the colour card, if it’s not already in the shot. It was a lot to think about, but we came up with a routine and all went smoothly. Although there were a couple of times when we forgot to change the camera… (Ah, hum, well, you know, we were working late in the dark galleries of the museum.)

VIL is used to detect traces of Egyptian blue—the first synthetic pigment ever made, used for thousands of years in ancient Egypt and known throughout the ancient Mediterranean. Naturally occurring blue minerals were either too precious or difficult to transform into large quantities of blue powder to create blue paint, so the Egyptians invented an artificial pigment.

Egyptian blue has the peculiar property of emitting infrared radiation when excited with a red light. Traces of Egyptian blue can easily be detected in the infrared spectrum—the pigment will glow a bright white. None of this is actually visible to the naked eye; shine as much red light as you want onto a work of art, you will not see the luminescence (bright white glow) because human vision does not extend to that part of the light spectrum. However, if you have an infrared (night vision) camera (usually a modified digital SLR camera with infrared filters), you can take an image of that luminescence. That’s what we did. We took photographs of all ancient marbles with the infrared camera when we used the flashes to excite the pigments. We found traces of Egyptian blue pigment on a few objects—some deliberately painted (like the sarcophagus fragment), others having been in contact with particles of the pigment but not actually decorated with it. (You can figure this out normally by the pattern or distribution of the luminescence.) The luminescence is so strong you can actually see single grains of Egyptian blue!

There is a great video about Egyptian blue on the British Museum website, click here to view it.  One of the photos below features Jimmy in the process of posting an image to Instagram.  To see what he posted, click here!

 

Pigment Busters

Following my ‘Searching for Colour!’ post, I got a few questions from family, friends and colleagues asking why we were actually looking for colour on our ancient marble sculptures.

We were looking for colour pigments on the marble sculptures because in ancient times most would have been coloured in some way! It seems inconceivable to us that these beautiful white marble sculptures could ever have had paint on them. But they often did. (Sounds gaudy, doesn’t it?) Sometimes, only details were painted; other times, they were completely covered by pigments or maybe part of them would have been gilded (covered in gold leaf). Or even perhaps have parts carved from coloured marble and assembled as one sculpture. This applies to Egyptian and other ancient sculpture as well (although those are not necessarily carved from marble).

Most ancient marble sculptures are now devoid of colour, the sun and rain having bleached or washed them away over the millennia. Thought to be ‘white,’ these ancient marble sculptures were the inspiration for statues carved during the Renaissance or the Neo-Classical period and those were NOT painted. That’s how we normally think of marble sculptures… white, the typical colour of marble. However, in nooks and crannies, you can occasionally find proof that coloured pigments were applied to those sculptures—in some cases visible with the naked eye.

During the two intense weeks of Classical marble study (and using various methods), Mark, Elizabeth, Noelle, Marianne and I went pigment busting…

 

Is this thing set to stun?

I’m exhausted. The last two weeks have been rather hectic, to say the least. There were several evenings when I didn’t get home until after 11pm… We’ve worked very hard on the classical marbles: we’ve examined the statues like we’ve never done before at the museum and used some weird equipment, too—it was great fun!

I’m too tired to go into details right now, so I thought I would share photos today and describe the various studies in later posts when I’m actually awake and coherent.

 

Hercules Under UV

A quick post to show you what I have been doing today with Mark (the marble guy) and Elizabeth (the student working with him). We spent the day with Hercules down in the bowels of the museum, illuminated by ultraviolet lights. No pigments on him, but under UV you can also see repaired breaks and whatever might be present on the sculpture’s surface (organic material, shellac, etc…).

All this 80s ultraviolet and industrial stuff makes me want to watch Blade Runner!