Skip to Content

Art Gallery of Ontario

Keyword Site Search

Art Matters Blog

Conservation Notes: Resurfacing Large Two Forms

July 30th, 2015

By Lisa Ellis, Conservator, Sculpture and Decorative Arts

Standing at the corner of McCaul and Dundas streets since 1974, Henry Moore’s monumental sculpture Large Two Forms has become an important part of Toronto’s cultural landscape. Scores of school children, families, local residents and out-of-town visitors enjoy sitting in the large void of the northern element, exploring and enjoying the surfaces and forms and now, perhaps more than ever, posing for photographs and selfies with the bronze giant.

Recently, the sculpture has begun to show its age. Those resting in the forms’ voids have inadvertently polished away the original textured surfaces. Pollution and moisture from the air have reacted with what was once a golden-brown surface, most notably on the top of the forms, turning it into a powdery light green corrosion layer. Worrisome stress cracks had opened up across welded joins and in the larger void where many visitors sat or stood for photos.

With generous funding and support from the Henry Moore Foundation, and after much planning and preparation, a small team of AGO staff members spent a month in the summer of 2015 addressing these issues.The treatment plan consisted of repairing stress cracks and attending to the appearance of the sculpture. Read the rest of this entry »

Conservation Notes: “I have seen my death!” and the very first X-ray

July 28th, 2015

By Katharine Whitman, Conservator, Photography

(photo at right) U.S. Military,  Operation Priscilla, taken at the moment of the shockwave, 1957.   / Camera Crew at Exact Moment of Shockwave Arrival, Nevada Test Site 1957. Gelatin silver print.

(photo at right) U.S. Military, Operation Priscilla, taken at the moment of the shockwave, 1957. / Camera Crew at Exact Moment of Shockwave Arrival, Nevada Test Site 1957. Gelatin silver print.

There’s something really amazing inside the AGO’s walls right now: a piece of medical history and the forerunner of technology used today. In our exhibition Camera Atomica, visitors can see a positive image of the first X-ray ever made. Wilhelm Conrad Röntgen, a physics professor in Worzburg, Bavaria, created the gelatine silver glass plate image, what would become known as the first “röntgenogram.” It captures the hand of Röntgen’s wife, Anna Bertha, and her wedding ring (the large dark circle). When she saw the image she is said to have exclaimed, “I have seen my death!” Read the rest of this entry »

Conservation Notes: A case for all types of photos

July 8th, 2015

By Katharine Whitman, Conservator, Photography

 American, mid- to late 19th century (artist), unknown sitter: portrait of woman standing, wearing dark jacket, 1865, ambrotype: sixth plate, case: brown leather with "souvenir" plate, gilt edges and clasp, interior with embossed red velvet pad, 21.12 x 38.55 cm. Anonymous Gift, 2000

American, mid- to late 19th century (artist), unknown sitter: portrait of woman standing, wearing dark jacket, 1865, ambrotype: sixth plate, case: brown leather with “souvenir” plate, gilt edges and clasp, interior with embossed red velvet pad, 21.12 x 38.55 cm. Anonymous Gift, 2000.

Adventures in Photograph Conservation: Cased photos

A photograph can be printed onto almost any surface. While paper is the most common substrate, others include metal, leather, plastic, cloth, canvas and glass, and many of these are represented in the AGO’s photograph collection. This is the first in a series of blog posts that will describe photographic processes and some of the hurdles a photograph conservator has to overcome while working with them. This instalment will cover the more common cased photographs: daguerreotypes, tintypes and ambrotypes. We’ll get to some of the more unique processes, such as the opaltype and pannotype, in another post.

Henry K. Sheldon, Mr. John Shields, Kingston, 1856, daguerreotype, tinted, 50.8 x 44.96 cm. Purchase with assistance of the Photography Curatorial Committee, 2008.

Henry K. Sheldon, Mr. John Shields, Kingston, 1856, daguerreotype, tinted, 50.8 x 44.96 cm. Purchase with assistance of the Photography Curatorial Committee, 2008.

Examples of these processes are often encased in leather-coated wood or sometimes in what were called “Union Cases,” which were made from a thermoplastic material. While some of the cases were larger, most were small enough to be held in one hand: these were precious, portable objects, often lined with silk or velvet, and many times contained the only existing photograph of an individual.

With the introduction of the daguerreotype in 1839 by Louis-Jacques-Mandé Daguerre (1787–1851), the dawn of photography, as it related to the public, had arrived. A daguerreotype is a photograph that consists of a mercury amalgam on a silver electroplated copper plate (right). The distinguishing visual characteristics of a daguerreotype are that the image is on a mirror-like surface of metallic silver: it will appear either positive or negative depending on whether a light or dark surface is being reflected in the image. The image was often also coloured with pigments to give it a more life-like cast. As an example of employment following the development of new technology, many of the artists who did this work were former miniature painters. With the introduction of photography in 1839, the demand for hand-painted miniature portraits declined drastically, and so it become common for photographers to have re-touchers and colourers on staff to apply the pigments.

Unknown america or canadian, 19th century (artist), seated woman at table, wearing gloves, 1880s, tintype, tinted highlights, 22.36 x 15.96 cm. Anonymous Gift, 2006.

Unknown American or Canadian, 19th century (artist), seated woman at table, wearing gloves, 1880s, tintype, tinted highlights, 22.36 x 15.96 cm. Anonymous Gift, 2006.

After the daguerreotype’s public introduction and adoption, many scientists started working on other, more economical photographic processes. In 1851, Frederick Scott Archer (1813–1857) introduced the collodion process. Ambrotypes and the tintypes (examples at left) are both collodion-based processes, the former being on glass and the latter on a thin sheet of darkly painted metal, usually tin or a ferrous material. The collodion in these processes is derived from solution of pyroxylin, or gun cotton, dissolved in ether and alcohol. Once coated on a piece of glass or metal, the collodion is sensitized in a solution of silver nitrate and exposed in a camera, and the plate is developed, fixed and allowed to dry. The resulting photograph is then varnished to prevent deterioration of the image. These photographs were much more resilient than daguerreotypes and — though conservators today would warn against it — some people would send their tintypes through the mail without a case, unconcerned about damaging the photograph.


Curious about Conservation?
If you have a burning question about Conservation, leave a comment below. We’ll do our best to give you an answer in an upcoming Conservation Notes post.


Signature Partner of the AGO’s Conservation Program


Conservation Notes: Displaying Henryk Ross’s powerful Łódź Ghetto photos

April 30th, 2015

By Katharine Whitman, Conservator, Photography

Henryk Ross, Negative #940 from Lodz Ghetto Collection Series, 1940-1944,  35 mm cellulose nitrate negative, 40.88 x 45.97 cm. Gift from archive of modern conflict, 2007.

Henryk Ross, Negative #940 from Lodz Ghetto Collection Series, 1940-1944, 35 mm cellulose nitrate negative, 40.88 x 45.97 cm. Gift from archive of modern conflict, 2007.

The exhibition Memory Unearthed: The Łódź Ghetto Photographs of Henryk Ross is rather unique for the AGO in that many different mounting methods are used to represent the powerful imagery of the photographs. It depicts the life in the Łódź Ghetto in German-occupied Poland: a work camp for Jewish and Romani people before they were sent to the Auschwitz and Chelmno concentration camps. We used a variety of display methods in the exhibition—pins, frames, magnets and custom-designed display cases—that work together to create a seamless display of period and modern prints.

New prints made from Ross's negatives, pinned to the wall of the gallery.

New prints made from Ross’s negatives, pinned to the wall of the gallery.

Unlike most exhibitions at the AGO Memory Unearthed includes many modern prints because most of the original images are only available in negative form. The negatives are nitrate-based and cannot be put on display for health and safety reasons. We put them into frozen storage, but before that we scanned them into a database and made new prints for the exhibition. To avoid detracting from the image, we opted to pin them to the walls of the gallery without frames (as above).

Prints sandwiched between Plexiglas.

Prints sandwiched between Plexiglas, with Japanese paper tabs.

This exhibition also includes period gelatin silver photographs, such as a folio of contact prints, identification cards, candid shots and wedding photographs. One of the more complicated mounting challenges we faced was how to minimally present Ross’s folio of contact negative prints safely and gracefully. The goal was to give the impression that the pages were almost floating in the case. To accomplish this, we:

  • affixed the folio pages to clear Plexiglas frames, which were then sandwiched in long sheets of additional Plexiglas;
  • attached Japanese paper tabs along the top edge, connecting the pages to Plexiglas frames;
  • used dry wheat-starch paste, a fully reversible adhesive, to attach the tabs to the folio pages;
  • and used archival double-stick tape to attach the tabs to the Plexiglas frames.

This method was successful, but to give visitors another way to view these important images, they are also projected on the wall near the presentation case in a film format (as in the photo below).

Gelber Gallery, where we are presentign the Ross folio.

Gelber Gallery, where we are presentign the Ross folio.

Learn more about the exhibition Memory Unearthed: The Łódź Ghetto Photographs of Henryk Ross here.


Curious about Conservation?
If you have a burning question about Conservation, leave a comment below. We’ll do our best to give you an answer in an upcoming Conservation Notes post.


Signature Partner of the AGO’s Conservation Program


Conservation Notes: Print on this

February 18th, 2015

carbon transfer 2001.169

P

By Katharine Whitman, Conservator, Photographs

Suzy Lake, The Natural Way to Draw, 1975. Colour emulsion transfer on uncoated canvas, 102.5 x 134 cm. Gift of nancy Hushion, 2009. 2009/107. © 2015 Suzy Lake.

Suzy Lake, The Natural Way to Draw, 1975. Colour emulsion transfer on uncoated canvas, 102.5 x 134 cm. Gift of nancy Hushion, 2009. 2009/107. © 2015 Suzy Lake.

Suzy Lake’s The Natural Way to Draw and other interesting photograph supports

Until the relatively recent advent of digital photography, in which many photographs exist solely as pixels on a screen, every photograph was printed. By far, the most common support on which to print has been paper. However, even since the early days of photography, they have also been printed on paper, fabric, metal, glass, ceramic and a host of other surfaces.

And now, with the advent of digital printing technologies, we can print photographs on almost any substrate. They can be ink-jet printed on to canvas, plastic, vinyl or paper: the possibilities are endless. As photograph conservator at the Art Gallery of Ontario, I’m fascinated by the wide array of other materials on which photographers and artists have printed their images. Read the rest of this entry »

Conservation Notes: Plastering The Grange

February 18th, 2015

By Claire Molgat-Laurin, AGO Conservation intern

Conserving the AGO’s largest artifact

The AGO’s largest artifact isn’t a monumental painting, or even a sculpture. Think even bigger.

Built in 1817, The Grange was the first building to serve as the home of the AGO, then known as the Art Museum of Toronto, and it is the oldest remaining brick house in Toronto — an important piece of history both for Toronto and for the AGO.

But over the course of the past few years, Jennifer Rieger, the historic site coordinator for The Grange, noticed that paint on one of the basement scullery walls was becoming powdery and blistered. This was a worrying symptom, one that indicated water was trapped in the walls and was damaging the plaster underneath the paint.

Henry Bowyer Lane British, 1817 - 1878, The Grange, c. 1840, overall: 28.6 x 44.1 cm (11 1/4 x 17 3/8 in.), watercolour on paper, Gift of Mrs. Seawell Emerson, Marblehead, Massachusetts, 1972, transferred from the Grange, 2008. © Art Gallery of Ontario

Henry Bowyer Lane
British, 1817 – 1878, The Grange, c. 1840, overall: 28.6 x 44.1 cm (11 1/4 x 17 3/8 in.), watercolour on paper,
Gift of Mrs. Seawell Emerson, Marblehead, Massachusetts, 1972, transferred from the Grange, 2008. © Art Gallery of Ontario.

A house like The Grange is like a living organism, with each part of its construction supported by another. If one component of the house is out of balance, it can affect the rest of the building too. The plaster covering the walls of The Grange should function as its skin, protecting the walls of the house and wicking dampness away from them.

Finding the root of this problem took some serious digging through the archives of the AGO to find records of previous repairs, sending samples of the materials in the wall to be analyzed by conservation scientists and consulting with a preservation architect to assess the exterior of the house. As we learned more about older repairs and the materials used, the situation started becoming clear: one of the problems with this wall originated during a restoration treatment that undertaken in the 1970s.

One of the most important principles in conserving artifacts and art is to use compatible materials that will react to the surrounding environment in the same way as the original components. The old restoration of the plaster in The Grange had been executed with materials that were thought to be compatible at the time. However, in more recent years, it has now been found that these newer, more mainstream materials definitely don’t combine well with traditional materials like those used in the original construction of the house.

Exposed structural wall in The Grange.

Exposed structural wall in The Grange.

The Portland cement and bonding agent used underneath the repaired plaster didn’t react to moisture in the same way as the original lime plaster layers. Instead of allowing moisture to dissipate through its surface, the bonding agent blocked the movement of moisture, causing the plaster to deteriorate and any attempted repairs to fail. The analysis of the materials also suggested that the wall was retaining moisture because the plaster hadn’t been left to cure long enough before the paint was applied, which didn’t allow the plaster to breathe.

To repair the plaster, we called in the services of specialists in heritage plastering — Ben Scott and James Sloan from the Lime Plaster Company. Both have a lot of experience working with historic buildings and know lime plaster inside and out.

According to Scott, working with historic houses like The Grange is complicated, but there’s one simple approach: every historic building is going to be different, and you can’t treat them all the same way.

Most of the time, going back to tried-and-true traditional methods is best. This is a new repair, but the materials have been used in construction all over the world for thousands of years: slaked limes, non-hydraulic or hydraulic limes, animal hair and assorted natural aggregates. The plaster used by Scott and Sloan is their own mix of aged lime putty plaster, unadulterated by any other materials that could be in ready-made mixes.

A closer look: Exposed structural wall in The Grange.

A closer look: Exposed structural wall in The Grange.


It’s a process that takes skill and experience and, most of all, time. Before starting the new treatment, they completely removed the old repairs, paring the wall down to its granite rocks to get a good surface for the plaster. They then applied several layers of plaster over the course of several weeks, starting with a strong “pricking-up” coat that prepared the surface for other layers, then gradually building up to the smooth outer finishing coat. Finally, the plaster needed time to cure as the lime react with carbon dioxide in the air and hardens, forming a strong bond.

The new lime plaster will allow The Grange’s wall to breathe again by effectively drawing moisture away from the walls to help protect the house. A well-executed plastering job like this will last a lifetime, like the original walls of The Grange.

“They don’t make them like this anymore,” Scott said, patting the wall of The Grange.

All the more reason to keep it breathing.


Curious about Conservation?
If you have a burning question about Conservation, leave a comment below. We’ll do our best to give you an answer in an upcoming Conservation Notes post.


Signature Partner of the AGO’s Conservation Program


Conservation Notes: Piecing together the past

November 25th, 2014

Figure 1: Examples of modern (left) and historic glass.

Figure 1: Examples of modern (left) and historic glass.

By Katharine Whitman, Conservator, Photographs

Picture this: you’re in your grandfather’s ancestral home. Under a stack of dusty photo albums you discover a small book-like box with a tiny metal clasp. You open it and find a photograph of a man with familiar features sitting stiffly before a painted landscape. It dawns upon you that it must be some distant relative, perhaps your great, great grandfather. Upon closer inspection, you realize that the image is in fact printed on a sheet of glass and that glass is cracked in two. What do you do?

As the AGO’s conservator of photographs, I’ve spent the past 10 years facing very similar situations. I have conducted research and taught workshops on a much neglected part of photography: the conservation of photographs on glass. This includes ambrotypes, opaltypes, wet plate Collodion, gelatine silver on glass and a host of other processes, many of which are represented in the AGO’s photography collection.
One of the pressing concerns in photograph conservation is how to deal with broken photographs on glass. Should they be repaired? Can they be repaired? In trying to answer these questions, a conservator must consider a host of factors, including: when the photograph was produced, the nature of the glass used, what photographic process was used and the value (monetary, sentimental or cultural) of the piece.

Imagine you needed to repair a sheet of glass that had broken in two. The logical way to do it would be to lay the two fragments on a flat surface, butt them against each other and glue their edges. However, it’s often not that simple.

Figure 2: A side view of historic non-planar glass.

Figure 2: A side view of historic non-planar glass.

Due to the glass-making processes prior to 1950, the sheets of glass used in photographic processes were not truly flat. This “non-planar” glass poses problems for conservators. Figure 1 is a comparison of modern glass, on the left, and pre-1950 historic glass, on the right. A bank of ceiling-mounted fluorescent lights is reflected in their surfaces. The reflection on the modern glass is undistorted because the glass is flat and the reflection on the historic glass is distorted because the glass is slightly wavy. You may have seen windows of old houses that look wavy and noticed how distorted any reflections look; that effect occurs because the glass is non-planar (Figure 2). This poses problems when repairing broken photographs on glass because when laid flat, the shards cannot be aligned properly. With this in mind, an innovative solution had to be found to accomplish the reassembly of broken historic photographs. The whole point of most photographs is to be decipherable, and if a photograph on glass is not in one piece, it loses its meaning and its full impact on the viewer.

Figure 3: A vertical assembly setup.

Figure 3: A vertical assembly setup.

The solution I determined, in association with the George Eastman House and the Corning Museum of Glass in Corning, New York, is an adaptation of a method created by Stephen Koob of the Corning Museum. It is the “vertical assembly” method, wherein the broken photograph on glass is assembled vertically, rather than horizontally. In this method, it is essential that the main shard is positioned perfectly aligned with gravity (Figure 3). Because glass is so brittle, it breaks very sharply. This results in a clean break, a shattering effect or a combination of the two. Vertical alignment ensures that the constant of gravity will pull the shards into position. This method of shard assembly is a completely new concept in photograph conservation.

There are many nuances to the repair of broken historic photographs on glass, and it takes a lot of experience and practice to master. If you have a broken photograph on glass it is best to contact the AGO conservation department for a referral to a conservator.


Curious about Conservation?
If you have a burning question about Conservation, leave a comment below. We’ll do our best to give you an answer in an upcoming Conservation Notes post.


Signature Partner of the AGO’s Conservation Program


Conservation Notes: A return to Betty Goodwin’s studio

October 27th, 2014


This is the third post in a series on the preservation and storage of Betty Goodwin’s notebooks. See the previous posts here and here.


Marianne Williams, Digital Special Collections Assistant in the AGO Library and Archives, has finished her project of creating new preservation enclosures for the 121 sketchbooks and notebooks from the late Montreal-based artist Betty Goodwin. Read the rest of this entry »

Conservation Notes: What’s (literally) behind Belle Époque posters’ longevity

September 3rd, 2014

Théophile Steinlen, Tournée du Chat Noir, 1896. Colour lithograph, sheet: 142 × 98.1 cm (55 7/8 × 38 5/8 in.). Gift from the Donald R. Muller/ Ross R. Scott. Collection through the American Friends of the Art Gallery of Ontario Inc., 2013. © 2014 Art Gallery of Ontario

Théophile Steinlen, Tournée du Chat Noir, 1896. Colour lithograph, sheet: 142 × 98.1 cm (55 7/8 × 38 5/8 in.). Gift from the Donald R. Muller/ Ross R. Scott. Collection through the American Friends of the Art Gallery of Ontario Inc., 2013. © 2014 Art Gallery of Ontario

In a post earlier this year we introduced you to Tessa Thomas, Samuel H. Kress Fellow in Paper Conservation at the AGO. Tessa is currently completing research and treatments on a group of Henri de Toulouse-Lautrec posters from the Ross R. Scott and Donald R. Muller Collection. Here is Tessa’s latest update on the progress of the project: Read the rest of this entry »

Conservation Notes: Preserving history on nitrate film

August 18th, 2014

By Katharine Whitman, Conservator, Photography

The Henryk Ross collection of negatives depict the Łódź Ghetto in Poland from 1939 to 1944, composing a valuable record of the conditions Jewish people faced during the Second World War. As with all film negatives from that period, they are on cellulose nitrate stock, a potentially dangerous medium due to the material’s tendency to release harmful gases when it degrades. Steps had to be taken to stop the deterioration of the negatives, and so they were recently digitally copied and put into frozen storage at the AGO.

Read the rest of this entry »