Ultrasonic Misting- Part One

I’ve been busy the past several months in the Paper Lab getting together the parts, purchase requests and wherewithal to construct an ultrasonic mister in order to care for a group of paintings needing some attention.

Last year, Lilly Library received a generous gift of over 450 paintings by the playwright, screenwriter and producer Clifford Odets https://blogs.libraries.indiana.edu/lilly/new-donation-the-artwork-of-clifford-odets/

Soon after the library received this gift, the Paper Lab hinged and matted nearly all of the paintings for storage and safer handling and access. During this process we noticed that a number of the artworks were suffering from condition issues related to the paint media that Odets chose. Much of the work relies on a layering method of drawing and painting over wax crayon. Odets would scratch through the pastel and gouache paints he favored to reveal the crayon beneath (a.k.a. sgraffito).

Here is a photograph of one such painting- on the back of a postcard- in raking light.

You can see how the teal blue paint has been scratched away to reveal orange, pink and purple wax crayon beneath. However, though the technique allowed Odets to create some wonderful images, it also created what we conservators refer to as inherent vice. There is little adhesion between the media layers and as the upper water-based paint layers dried, they began to shrink in place causing minute cracks and more seriously, flaking and loss. This close-up shows what I mean (poor little flaky fish!)


In these circumstances, conservators perform a process called consolidationTypically, the consolidant is a type of adhesive carefully chosen for a number of factors including, but not limited to, compatibility with the object physically, visually and chemically, ease of preparation, ease of application, quality of bond strength and ageing characteristics. Normally, the process would be carried out under a low-power microscope using a small brush and delicately applying the consolidant to the cracks and underneath the lifting paint, fastening it back down. With these paintings the scale of damage prohibits such an approach- the fish above is 2cm long, which makes each of the tiny flakes far smaller than a millimeter in dimension. My fine motor skills are excellent, but not that excellent!

Another method is called for: that of Ultrasonic Misting. Developed by the Canadian Conservation Institute in 1990, the ultrasonic mister allows greater control of the whole process of consolidation of powdery paint and pigments. Unfortunately one can’t readily buy such systems- at least not at affordable rates for an aerosol generator- so I set out to construct one myself. There are a number of published articles explaining how to make one as well as a number of institutions who have blogged about it in the past, such as this account from the UCLA/Getty Conservation Program. Within a month or so I had purchased and cannibalized the necessary parts and had it up and running:

What the device consists of is a domestic ultrasonic humidifier, with the upper water reservoir removed. We use this very humidifier routinely in the lab for the relaxation of library materials, so it was good to have on hand! Resting in about one inch of water over the oscillator within the humidifier is a LDPE plastic bottle containing the consolidant adhesive. Ultrasonic frequencies generated in the base of the humidifier travel through the bottle and cause cavitation to occur, generating a fine mist of adhesive to rise from the liquid. A pump (the large white cube in the background to the left) was borrowed from our vacuum suction table to drive air into the bottle (through the clear tube entering the back of the bottle), and then the adhesive-laden water vapor finds its way out the top, through another length of tube to be emitted through a small applicator nozzle. Also sitting in front of the device is the consolidant of choice. Can you guess what it is? There is a clue in the painting I chose to include earlier…

Next week, I’ll cover the pros and cons of the design and talk about the success of the treatments.

Raman Spectroscopy in the Lab

This past November I had the pleasure of working with a newly acquired piece of   equipment- an Agility™ Transportable Dual-band Benchtop Raman Spectrometer to be specific.

Vendor photo of Agility with a bottle of Cab' Sauv'
Vendor photo of Agility with a bottle of Cab Sauv

By way of background, a small team of various campus departments and research centers* was assembled over the past couple of years- all of whom are interested in exploring research interests related to analysis of cultural heritage materials. We applied for some internal funding this past year through the Office of the Vice Provost for Reaearch and were awarded a “Collaborative Research and Creative Funding” grant over the summer for the purpose of purchasing said piece of equipment.

What is Raman Spectroscopy?  In a nutshell, it is an analytical tool by which laser light interacts with molecular vibrations resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Basically, a machine shines a monochromatic laser at a substance and after some filtering, measures the shift in the radiation (in this case, light) coming off of it to give us an indication of its molecular nature. This is the sort of output one gets which then needs to be interpreted- the spectrum for red lead pigment:

Courtesy of www.cameo.mfa.org
Courtesy of www.cameo.mfa.org

IU Bloomington already has a very sophisticated Raman spectrometer within the Department of Chemistry, but this new acquisition lets us to take the process to the object- important when examining rare items of cultural significance. This form of spectroscopy allows conservators to analyze materials in-situ in a non-destructive manner ie. other forms of analysis can require a sample to be taken from the item in question which will be destroyed in the process. Increasingly, analytical methods are being adopted which leave the item unharmed.

In practice, there is still quite a lot of skill needed to operate the machine and interpret the results. I was able to devote a day or two to learning the operating system, begin to understand the variables involved with adjusting the actual laser excitation (very important as misapplication can lead to irreversible changes in the material analyzed), and understand the difficulties of interpreting a series of peaks on a graph. There are spectral libraries available which automate the process, but the pharmaceutical library that came with purchase won’t help us out much when analyzing 17th century maps or archaeological daub from Paleo-Indian settlements, unless of course we’re looking for acetaminophen! Still, it will be a very valuable and collaborative tool to have on hand.


* Departments include: Department of Chemistry, Department of History and Philosophy of Science, Chymistry of Isaac Newton Project, Glenn Black Laboratory of Archaeology, Lilly Library and us, here in Library Preservation.

Midwest Regional Conservation Guild 2015 Annual Symposium

I found myself travelling to the beautiful University of Michigan campus in Ann Arbor the weekend of October 2-4 for the annual symposium of the Midwest Regional Conservation Guild. Our own preservation lab and other conservation professionals on the IU Bloomington campus hosted this group in 2012; it was now Michigan’s turn. The Kelsey Museum of Archaeology, also known as Newberry Hall was to be our base for the weekend.


The event got off to an excellent start Friday afternoon with tours of the various conservation labs: both Papyrology and Special collections on the Michigan campus, and the Detroit Institute of Arts and The Henry Ford Museum within the region. I toured the campus labs, and was impressed by the Special Collections lab within the Buhr Building.  Though this building was originally a ball-bearing factory, now repurposed as an off-site library facility, I found parallels between it and our own ALF building here on campus.  The Buhr facility holds 2.5 million volumes and houses a very well-equipped, pleasantly lit conservation lab much like our own. After a special curator-led tour of the current exhibit at the Kelsey, the evening ended with a pleasant opening reception giving all participants a chance to catch up with colleagues old and new.

Saturday presented itself with a full day of session talks. From the perspective of a paper conservator at a university library, I found several to be of interest though many more were given than I can cover in this post:

Christopher Foster, Conservator of Art on Paper and Photographs at the Detroit Institute of the Arts gave a very informative talk about the analytical work that went into studying eight of Diego Rivera’s cartoons for the Detroit Industry frescoes at the museum. These preparatory drawings which at first glance seemed simple renderings in black and red media on paper revealed themselves to be complexly constructed. The skill of Rivera’s hand and eye became more apparent to conservators and curators alike after studying the composite materials by traditional microscopy as well as Raman and FTIR spectroscopy.

Though not concerning a work on paper, Cybele Tom (Assistant Conservator of Objects and the Art Institute, Chicago) gave an insightful talk about the thought process which went into the conservation of a soon-to-be-exhibited early 16th century polychrome wood sculpture. A thorough technical study brought to light several previous restoration campaigns which left an ‘aesthetically disparate surface’  for the conservator to contend with. Her task was to ‘arrive at a coherent form that still honors its 500 year history’. Concepts that we as conservators ruminate over daily, such as old vs. new, varying theory of originality, preservation of evidence, and culturally-biased interpretation were discussed.

Janelle Batkin-Hall, Conservation Intern, Kelsey Museum of Archaeology, gave an informative, if sometimes skin-crawling, talk about Victorian-era hairwork. From time to time, examples of this craft reveal themselves within collections here at IU so I was thankful for her background study, analysis and treatment examples.

Tom Edmondson, Heugh-Edmondson Conservation Services LLC, Kansas City, gave an excellent case study of the treatment of a convex crayon enlargement portrait. We have a number of these early photographic processes within our collections- I enjoy working on them for the challenges they often present the conservator. Tom relayed some approaches and techniques to working with them that I hadn’t considered, but will experiment with in the future.

Jodie Utter, a paper conservator at the Amon Carter Museum of American Art in Fort Worth, gave an excellent presentation showing how the skills and work of a conservator can shed light on curatorial questions and aid art historical research. She studied several examples of Charles Russell’s iconic Bronc Twister, aiding in the understanding of this image’s development by the artist as well as its commercial use by a pharmaceutical company as its logo for a laxative awkwardly named Heptol Splits!

After an ambitious schedule of talks, the day ended with a very generous reception at a local restaurant and cocktail bar- the warmth of the professional company overcame the blustery weather outside.

Sunday morning brought us another three presentations, including one that I delivered concerning the recent collaboration of 3-D scanning and modeling technology with automated enclosure manufacture. I hope that our experiment will be of some use to other institutions who may have the necessary technology on hand.

Finally Heather Galloway, a private conservator from Oberlin Ohio, presented a talk about her work bringing conservation into the undergraduate and graduate classroom. This topic, and her approach to creating a curriculum, resonated with me and the teaching I do within IU. Even though the conservator in an academic setting generally does not educate students in remedial conservation practice, our profession has much to share beyond the typical lab tour. Heather works with both art history and physical science students, presenting university art collections in a new light to supplement their core educational instruction.

I left the symposium mid-day on Sunday to return to Bloomington with a renewed enthusiasm about the work we do as conservators. Over the span of my career I’ve seen a number of changes to the profession- both good and bad. One of the more positive changes illustrated this weekend was that conservators are increasingly working in concert with other museum and academic professionals. Our skills and insight provide valuable information which can supplement other fields of enquiry. In turn, we’re reminded that our work has an effect outside of our traditional environment of the lab and storage area.

Hornak Drawings Conservation Treatment

This month we worked on three drawings by Ian Hornak, an American artist who worked in the late 20th century. His early work consisted of erotic pen and ink drawings and later consisted of photorealistic landscapes and portraits in acrylic on canvas.

One drawing had masking tape around the edges, another was spot-adhered to matboard, and the third was fully-adhered to matboard. All three had surface dirt and minor tears.


Our treatment plan was to remove the matboard, surface clean the drawings, spot-test and wash the items, and lastly, mend any tears with paste and Japanese paper.


If you look closely, you may be able to see the graphite under-drawing. A real treat was seeing an initial sketch on the back of that same drawing.


These pieces will be included in an exhibition at The Kinsey Institute, opening next month. The opening reception will be on January 24th from 5-7pm with an introductory talk at 4pm by Eric Ian Hornak Spoutz, the artist’s nephew and Executive Director of the Ian Hornak Foundation. Hope to see you there!

Ian_Hornak02 Ian_Hornak03

For more information on the exhibit please visit:

And for more info on the artist:

-Arini Esarey