Category: Specialty Sessions

Posts on talks that were presented as part of the specialty sessions at AIC’s Annual Meeting

AIC’s 40th Annual Meeting, Research and Technical Studies Session, May 10, “Digital imaging analysis of writing materials using Photoshop Assisted Spectroscopy”, by Kristi Davenport, Holly Herro, Peter Gabriele

NB: Before I try to blog about this talk, I need to say that…well, we didn’t really ever get to discussing Photoshop Assisted spectroscopy! Meaning, this blog will contain some interesting tidbits but you won’t be learning much about this technique or how you might use it in your lab/institution. Sorry!

The project highlighted in this talk was the analysis of the logbooks and writings of Dr. Nirenberg, a Nobel Laureate. Dr. Nirenberg cracked the genetic code (our DNA) and his writings are considered a national treasure. The bad news is that all of his writings were made using ballpoint ink and ballpoint inks are notoriously fugitive. This project used the Photoshop Assisted spectroscopy (is this just kind of like hyperspectral imaging???), and interviews with Dr. Nirenberg’s former technicians to figure out what different markings mean in the logbooks and writings (eg, there are occasionally red marks in the books which were used by Dr. Nirenberg to indicate points/data/results of interest). Also, drops/stains on the charts/files turned out to be because solvent was accidentally dropped onto the books during lab experiments.

http://en.wikipedia.org/wiki/Marshall_Warren_Nirenberg

INKS
* First ballpoint pen was patented in 1818; the pens were used to mark leather
* The inks contained within are not very archival and weren’t designed to be
* Ball ink is used by some artists and it will fade with time
* There are a lot of components in ink; dyes and pigments; solvents, resins, emulsifying agents, lubricants, viscosity modifiers; optical additives; anti-corrosives;
* The rolling ball at the tip of a ballpoint pen is supposed to plow through the ink, pushing it onto/into the paper. You can get buildup of ink at the front of the pen if the pen doesn’t work well and results in those goopy clumps you sometimes get;
*As soon as the ink comes out from the interior, the ink is oxidizing
*The roller ball can pick up residue from the surface of the paper and roll it back into the ink reservoir – this is not good because you can get a build up of garbage interacting with the ink.
*All new inks that are out there have fluorescing agents in them – to make ink look brighter with the artificial lighting used in most office spaces – this is a way you can differentiate modern inks from older ones when examining documents
* ballpoint ink pens is a $20 Billion/year business; the entire idea is for you to keep buying these products
* Before 1949 – inks in pens were oil based; these inks are very stable and you can use this information to help you differentiate when inks were applied to a substrate
* black ink is black because it has all the chromophores in it; when it degrades/separates, it changes color; other colors fade
* All inks have different fingerprints

When you get a historic document, you don’t know starting point of original ink. But you can look at the current state of the ink and you can start to understand degradation process.

SCANNING DOCUMENTS
A scanner is actually a spectrometer. Every pixel has an RGB value, but the computer mixes the colors for your eye. However, you can use those same values in a more creative way: If you consider the RGB values as values for a three dimensional space, you can use the values to plot them on a 3D map and track different types of inks used on historic documents.

AIC’s 40th Annual Meeting – RATS morning session, May 10, “Atomic Layer Deposition (ALD) films as protective coatings for silver”, by Amy Marquardt, Glenn Gates, Eric Breitung, Richard Ash, Gary Robloff, Ray Phaneuf, and Terry Drayman-Weisser*

*nb: the title of this talk, the author list, and author order all changed from what was published in the program. If I have left out an author name, I apologize.

The focus of this talk was to discuss the application of atomic layer deposited films of aluminum oxide (Al2O3) onto sterling silver surfaces. Ultimately, it is hoped that this process will be refined for use with sterling silver art objects in museums.

The overarching goals of this project are to find a coating for silver that is long lived; slows the diffusion of sulfur to the surface of the art object (I learned this fact at the presentation by Zeev Rosenzweig at the RATS luncheon); can be rapidly applied and covers the object homogeneously; is removable; and is less labor intensive than manual application and mechanical polishing.

(wow, that’s a lot!)

The University of Maryland has a “BENEQ TFS 500”, a commercially available atomic layer deposition (ALD) machine/instrument, to deposit thin film coatings on anything that is placed inside of it.
http://www.beneq.com/tfs-500.html

Awesome facts of this instrument:
• Samples placed in the instrument can touch one another and it won’t affect deposition;
• You can coat MANY samples all at the same time
• You can control the thickness of the layer you deposit onto the objects you place inside the instrument, down to the nanometer (nm) thicknesses
• Coatings are incredibly uniform
• The films made are dense (ie, tightly compacted), and these types of films make good vapor barriers
• Coating will go into very small crevices and tool marks
• Tailoring thickness allows you to control optical properties
• It can take a mere 1 hour to make a coating that is 100 nm thick

The project is currently examining whether aluminum oxide coatings perform better than nitrocellulose ones. They used accelerated aging studies (40°C, 30-50% RH, 20 ppm hydrogen sulfide pumped through a sealed chamber) on coated samples and performed Tarnish Rate Analysis (never heard of this!! measure color of tarnish; correlate to thickness of tarnish layer), X-ray photon spectroscopy (XPS), secondary ion mass time of flight mass spectrometry (SIMS-TOF), and atomic force microscopy (AFM) to analyze this.

RESULTS and CONCLUSIONS:
* A 80 nm aluminum oxide coating outperformed a microns thick nitrocellulose coating because it is more tarnish resistant than nitrocellulose.

* They said that that these results are very fresh and new but that the aluminum oxide coatings are removable with a minimal loss of surface copper and silver using dilute sodium hydroxide (NaOH) but that you have to be careful about the concentration of the NaOH because it can selectively remove copper over silver from the sterling silver alloy itself. But that we should all relax because the amount of copper or silver being removed is on the nanoscale.

Q&A session:

Comment: Eric presented removability study with weak NaOH compared to data from Glenn (I don’t know if this work is published or has been presented elsewhere), who used three different chalks (all of which were in the lab);

Q: is this atomic layer deposition instrument expensive?

A reactor costs…$500K. BUT you can build one or buy the parts separate and assemble one yourself; not rocket science to build one; there is a place in Cambridge (MA? England?) that sells on for <$100K; you can make a homemade one for ~$50K

Q7: how long will coating last?

At least 20 years; a guess, no hard evidence

One facet of this project is to build coatings even better than aluminum oxide

TERRY Weissman: lot of the current results presented here are theorhetical; we will be getting into more of the conservation issues as time goes along;

Also, we knew that NaOH would affect the copper; but often times, art objects are already Cu depleted; We might find a better solvent in the future

AIC’s 40th Annual Meeting – RATS morning session, May 10, “Progress in the investigation of silicone rubbers and their residues”, by Kasey L. Hamilton, Adriana Rizzo, and Anna Serotta

The focus of this presentation was to address problems associated with the use of slow and quick setting silicone rubbers for objects conservation applications. The main problem is that silicone rubbers often leave behind liquid and solid residues on objects after they are used. While it may be possible to physically remove the solids, the liquid residues often result in the development of a stain on the surface of the object where the silicone rubber had been applied. The question becomes, what is the chemical make up of these stains and can they be removed using solvents?

Why are we using these silicone polymers in the first place?
• to make casts for recasting
• to allow you to see an image or tool marks inscribed into a object better than you can see them on the object itself (silicone rubbers are homogeneous in color while objects themselves may not be)
• to non-invasively investigate the surface topography of the artifact

The research project entailed selecting eight different silicone rubbers and applying them to a series of different surfaces (plaster discs, limestone, and glass). Following removal of the silicones, attenuated reflectance-fourier transform infrared spectroscopy (ATR-FTIR) was used to determine the chemical make up (O-Si-O and Si-CH3 bonds) and depth of penetration of the liquid residues left behind. Several types of mass spectrometry (evolved gas, pyrolysis gas chromatography [PYGC-MS]) were used to study the eight rubbers and the molecular weights of the materials that are excreted out of the silicone rubbers and left on the different substrates.

RESULTS AND CONCLUSIONS:

* Hexane can be used to remove some of the staining material. I wasn’t sure how this conclusion was drawn? Regardless, it was a better solvent than either methanol (or was it ethanol) for removing some of the residue.

* When residues were observed, the color of residue was related to the color of the mold/silicome material

* Residues are mainly high molecular weight (HMW) components of the silicone rubber and are in their polymeric form – this wasn’t necessarily an expected outcome but it was what was observed

* It wasn’t possible to do a quantitative comparison of the amount of residue left behind between different rubbers

* Slow setting silicone rubber is bad for porous surfaces and residues can penetrate up to 100 microns into the surface (depending on the porosity of the object)

* Given the same rubber, the amount of residue left behind is a function of the material its applied to (intuitive?)

*Siloxane residues are comparable for quick setting rubbers

*Residues maybe reduced, but it is unlikely that they are effectively removed even with non-polar solvents

* There were a couple of others, but future work is to see if barrier coatings (methylcellulose) will help prevent residue deposition.

COMMENTS made following the presentation:

Baltimore museum stopped using silicone rubbers years ago; using silicones on rubbers causes patinas to disappear – patinas were saturated with silicone residues; little bits of set silicone were stuck in interstices of porous surfaces;

• I was surprised – atr is not really ideal for depth of penetration analysis; I also don’t think you can examine an area smaller than 20 um wide; can be hard to measure depths of penetration very accurately)

Any idea how porous the plaster is? Gypsum plaster – can you measure porosity?

Made sure used same batch of plaster throughout the experiments

AIC’s 40th Annual Meeting, The Creation, Implementation, and Safety of Digitally Printed Fabrics in Textile Conservation: Where are We in 2012?, by Miriam Murphy

Author Miriam Murphy, Kress Conservation Fellow, Museum Conservation Institute, and National Museum of African History and Culture, Smithsonian Institution, presented a review of digital printing techniques and their use in textile conservation. This was a great refresher for colleagues who have not kept up with advances over the past decade, including your’s truly.

There are seven steps in producing digitally printed textiles. Step 1 is the digital capture, using scanner or camera. Often this is done by the conservator.

Step 2 is image processing, which is bet left to the printer in order to produce accurate results and avoid hair-tearing-out by the conservator.

Step 3 is color management, for which a color blanket is an essential tool. This is a full printout of colors on the chosen substrate, best compared to the source object in the same lighting as eventual display, ie the gallery or historic house. The small fee for this color blanket is well worth the investment.

Step 4 is the printing process. Although 600-700 dpi is available, 300 is usually plenty good. Printers can print up to 138″ wide and are often constrained only by the size of the image file.

Step 5 is choice of ink. Pigment based inks are the best choice because they require no pretreatment to the substrate and dry with heat. They are susceptible to breakdown in extreme light conditions and with abrasion and much washing. Dark colors can also be hard to achieve and contrast between adjacent dark colors is not always great. Museum conditions usually can accommodate these limitations.

Step 6 is choice of substrate. There are many, many available substrates, but cotton remains the best choice for museum applications. The weave structure of the original does not have to match because the image will provide this detail. Fabrics are available form the printer or from TestFabrics or Jacquard Inkjet Fabric Systems.

Step 7 is pre and post treatment assessment–I confess my notes are sketchy about this step.

If you are interested in speaking with digital print houses, Ms Murphy suggested several including Super Sampler, First2print, LTS Design Service Corp and Digifab, most of which are in NYC, I believe.

The benefits of digitally printed fabrics in museums has been outlined elsewhere, but highlights include quick turnaround, high resolution, and increasingly small dye runs. Why aren’t we all using this technology??!!

AIC’s 40th Annual Meeting, A Successful Treatment Method for Reducing Dye Bleed on a 19th-Century Sampler, by Katherine Sahmel and Laura Mina

Conservation of an 1832 Scottish sampler in the collection of the Philadelphia Museum of Art was begun by Winterthur student Katherine Sahmel while an intern at the PMA and continues with FIT student Laura Mina, the current intern.

This outstanding sampler is part of the Whitman collection and is notable not only for its design but also for its provenience and the existence of photographs of the main building depicted in the embroidery. Prior to acquisition, the sampler was apparently washed causing extensive bleeding of green and red dyes. It has not been exhibited due to this unfortunate condition.

The dyes were analyzed by Ken Sutherland using FTIR, identifying Indigo Carmine as the probable blue component of the fugitive green dye.

Initial tests to reduce the dye bleeding with standard solvents and surfactants were not fruitful so Ms Sahmel applied the modular cleaning system developed by Richard Wolbers. Tests on small samples of threads from the back of the sampler led to the choice of a combined cleaning solution of EDTA (ethylenediaminetetraacetate)1% and TEA (triethylanolamine) .5%.

This system for cleaning requires extended contact with the textile, minimal wetting, and protection of surrounding embroidery threads. Cyclododecane was applied to the front and back adjacent embroidery yarns. A poultice of cleaning solution in methyl cellulose was then prepared and applied to the dye bleed. After treatment the methyl cellulose was removed and flushed with revcerse osmosis water before drying the treated area under suction.

The pros to this treatment was successful removal of dye bleed with minimal effect on adjacent threads. Cons include difficulty in clearing the methyl cellulose poultice and the high ph of the cleaning solution on the wool threads. When Laura Mina took over the project she modified the poultice to use agaros gel, which is easily prepared and removed. The cleaning solution was adjusted to add more TEA.

This research has wise applications in textile conservation, and sampler conservation in ap[rticular. It is non hazardous and requires no fume hood. Stay tuned for an exhibit of the Whitman Samplers coming to the PMA.

AIC’s 40th Annual Meeting, Repair of 20th-Century Leavers Lace, by Annie-Beth Ellington

Lever’s Lace is a type of machine-made lace that provides a similar product to hand-made bobbin lace. Its structure and relatively low-status in museum collections have made it an uncommon target for conservation treatments. The author’s graduate thesis research for her MA at the University of Rhode Island both brings to light this historic textile and provides guidance in how to undertake stabilization of damaged samples.

In 1813 John Lever modified a loom to make Lever’s Lace, and subsequent addition of Jacquard technology in 1849 increased the range of the product. It was imported to the US in 1910 to make mosquito netting and other simple structures, eventually creating the decorative lace familiar to many people. Lever’s lace consists of a ground of twisted warps. Patterns or ornaments outlined by a heaver thread are accomplished with bobbins.

The author experimented with mock-ups of the structure to better understand the challenges of repairs. She then tensioned a piece of damaged lace over a black fabric-covered board. A photocopy of the pattern area was inserted beneath to act as a guide. Using a microscope, she floated 40 denier nylon threads across areas of loss following the pattern. The author quickly found that intervention could cause additional unraveling of damages areas, so she changed to using Jade adhesive on broken thread ends prior to repairs.

Repair of Levers Lace is slow and dyeing nylon thread to match colors would only add to the project time. However with further development this technique will guide future conservators.

AIC’s 40th Annual Meeting, Recovery and Conservation of the Textile Collections at the National Museum of Music, Alina Vazquez De Arazoza

Alina Vazquez de Arazoza is one of 20 Latin American colleagues who were able to join us at the 40th Annual AIC meeting thanks to funding from the Getty. Ms Vazquez requested that our colleague Amparo Ruedas read her paper to the TSG.

In 1971, a former Colonial mansion located in Havana was converted to the National Museum of Music. It contains, among its diverse collections, costumes of prominent Cuban musicians and banners from musical groups. The majority of collection dates to the 20th century, but several important 19th century items are also preserved. Among these is the glove of Perucheo Figueredo, the author of Cuba’s national anthem, and great great grandfather of Amparo Ruedas, giving added meaning to this presentation.

The renovation of the museum building provided the opportunity for the author to survey the collection, undertake conservation treatments prior to rehousing and exhibition, and do biographical research into the artists represented by the collection. She worked in collaboration with CENCREM (Centro Nacional de Conservacion, Restauracion y Museologia) which provided a facility and analytical assistance, all at no charge!

In general the collection was in fair condition. Items were dirty, distorted from poor storage, and dry, despite the tropical climate and lack of adequate environmental conditions. Humidity had taken a toll on some items, however, as seen by corroded metal trims, associated staining, some water damage with dye migration, and some insect damage. Much of the collection also exhibited yellowing.

The author undertook analysis of items in order to prepare a proposal for conservation. SEM results confirmed fiber content of organic and metal components. Much of the collection is hand made, though industrially produced items and commercial labels were noted and researched. The presence of prior repairs were documented, as well as types of adhesives that had been employed. Parameters of the conservation project were set out identify which textiles needed surface cleaning, aqueous or solvent cleaning, which prior repairs would be reversed.

What impressed me most about Ms Vazquez’s and her project are the advanced level of treatment skills, storage and conservation materials, analytical tools and connoisseurship compared to other parts of Latin America and the Caribbean that I have visited. This conservation project was equal in all ways to similar projects undertaken in the United States, which happily dispelled my notions of the ability of Cuban conservation professionals to achieve a high level of skill and accomplishments.

AIC’s 40th Annual Meeting- Objects and Research and Technical Studies Joint Session, May 9, 2012 “www.chemistryinart.org: Chemistry in Art Scholars– A Virtual & Real Community” by Hill and Odegaard

I’m not an educator, but while listening to this talk I was thinking “Sign Me Up!”. Dr. Hill spoke about the intensive workshop provided for educators who want to improve their science classes or start new ones. She’s a professor at Millersville University and wants conservators to know that chemistry professors are safe to connect with! The overarching program of cCWCS (Chemistry Collaborations, Workshops, and Communities of Scholars) covers many topics, but she focused on those that combine chemistry and art. You can check out their website (there was a typo in the original talk title) and find lots of materials if you aren’t able to attend the workshop or you’re just interested in finding out more about what they do. If you are thinking about starting a class or want to improve a class that you already give this 5-day intensive workshop might be for you. And it’s all expenses paid, thanks to the NSF. Their target audience is undergraduate faculty and staff and includes mainly chemists, practicing artists and art faculty. They are interested in having more representation from the conservation community. It sounds like a fun way to get the word out about what conservation is and what conservators do as there is a high degree of confusion about the difference between curators and conservators amongst this group. Also, you could potentially make some helpful contacts in the chemistry world.

The participants come from all over the country and generally fall into four categories:

  1. those how are looking for a fancy vacation (really a minority)
  2. older faculty who now have more flexibility in their schedule and are looking to pursue interests outside of their previous research and bring excitement to their students
  3. mid-career faculty who are looking for a unique area of research or trying to find their teaching niche
  4. and community college faculty who are looking for support and to bring interesting applications to students to engage them and get them more enthusiastic about science.

Vicki Cassman is an example of one of their alums who attended a session in 2010 and took what she learned back to UD for an honors seminar.

In 2009 they started an advanced workshop, the third of which will be held this summer. During this workshop they discuss ethics and understanding the questions you are trying to answer before starting analysis. Participants can bring an object that they have questions about and then they share the results with one another.

In the future they are looking for ways to broaden the community and making resources available to educators. Thanks to Nancy Odegaard and Dr. Hill for bringing this to our attention.

AIC’s 39th Annual Meeting- Textiles Session, June 2, “The “Observer Effect” in Conservation: Changes in Perception and the Treatment of a Man’s Silk Suit, c. 1745” by Laura Mina

This talk was in interesting treatment case study of an 18th c suit, including some detective work about what has happened to it throughout its history.   Ms. Mina also attempts to draw parallels between treatment decisions made throughout the history of the piece, or conservation decisions in general, and the “observer effect” from quantum mechanics.

The suit is from the Museum of the City of New York collection and consists of a coat and waistcoat but no breaches.  The suit was a very fashionable garment when it was created in 1745 and, as frequently happened with beautiful and expensive clothing, it was sold and resold many times.  With each new owner, alterations occurred to suit their needs, creating a confusing mix of stitches and patches.  Finally the suit was donated to the Museum of the City of New York in 1938.   Even then it appears the suit wasn’t spared alteration, but in the name of restoration.   Ms. Mina then described the treatment she undertook and part of her rational for the treatment.  This piece required patience to excavate its many layers of interpretation.

AIC’s 39th Annual Meeting- Texiles Session, June 1, “On-line Access to and Preservation of a Multi-Component Sketch Collection” by Marjorie Jonas

This talk discussed the re-housing and development of a database for a collection of design sketches by Bonnie Cashin within the FIT Archives and Special Collections (SC) at the Fashion Institute of Technology (FIT).  Bonnie Cashin was a 20th Century fashion designer that designed clothing and accessories with this collection of sketches representing her work for the Phillip Sills Company.   More than 4000 sketches with accompanying fabric swatches and ephemera had been pasted into a spiral bound sketchbooks originally, but various sketchbooks had been unbound with the pages loose in boxes and other books remained intact.   The collection had only minimal catalog information and this along with its various housings made its use difficult and required unnecessary handling.  For this project, the sketch books were unbound because many of the plastic bindings were failing and pages were sticking to each other.  All sketch book pages were re-housed, first into 3 ml polyethylene bags and then archival boxes.

The main point of the talk was describing a finding aid that was developed to improve access to the collection and reduce the amount of handling the sketch pages encounter.  This finding aid is an online database with 10 categories that includes catalog and biographic information, with hyperlinks to images of the pages and associated materials.  For this finding aid each sketchbook page was given a unique number based on the ISAD(G) archive numbering standard.  The database is keyword searchable through the FIT library site.   This project has improved access to this collection while reducing handling and the searchable database concept is being used for other archive collections at FIT.