In November 2003 the Cowen Gallery was opened to the public, displaying 134 paintings and 16 sculptures belonging to the collection of the State Library of Victoria. I first began working on the State Library of Victoria's painting collection in 1995 as a conservator in private practice. Then, in 1997 Christine Downer, the Picture Librarian, proposed a list of paintings for exhibition; and I was appointed to the position of Supervising Conservator, Paintings. My original brief was to document each painting and frame, but it soon became obvious that many of the paintings were in very poor condition and so began the long-term project of the conservation treatment of the paintings collection.

Conservation has become an accepted term to describe the preservation of our natural environment, but it applies equally to our cultural heritage. Conservation is a highly technical task based on knowledge of the structure and chemistry of the materials involved. It includes preventative action through environmental monitoring, and in many cases involves a hands-on approach using treatments to stabilise and repair objects. The primary focus of any treatment is to preserve the item for the future. This can involve consolidation to stop an artwork from falling apart; it can involve cleaning to remove differing types of surface dirt from corroding the top layer of an artwork; it can involve applying a protective layer to the work to inhibit further deterioration of the surface of the work. These treatments are all designed to preserve the artwork. Where needed, restoration techniques are employed to enhance the aesthetic nature of the work. In the case of paintings conservation, this may mean that there is an area of the paint layer that has been lost due to a tear or flaking; this area will need to be inpainted to match the original tonal values of the artist. The area is re-integrated visually so that the eye of the viewer is not distracted and immediately drawn to the fault area but is left to appreciate the work as a whole. Because this part of the treatment is purely aesthetic it is called restoration. The majority of what we do is to preserve the work for the future, so the overall term for the preservation and restoration of an artwork is conservation.

Not all of the paintings in this collection could be regarded as masterpieces but each reflects a part of our cultural history of Melbourne that makes the individual work important. I have selected four paintings to illustrate the sort of work I have been doing. I chose them because of the enjoyment I received from treating these works and because they identify different areas of specialized treatment.

The first painting is South Wharf, an oil on canvas by H.N.E. Cook of Queens'Wharf in 1883. The painting looks west from the South Melbourne side of the river and gives an unusual and almost melancholy perspective of what was generally a very busy wharf. When it came into the paintings conservation laboratory, the painting was very discoloured by both surface dirt and a layer of aged resinous varnish. There were two tears that had been poorly repaired and a small hole as well as staining in the sky area. The painting was cleaned using a different range of organic solvents. The hole was patched and infilled with a wax/chalk mix to give an even surface on which to paint. The loss area was inpainted to match the original colours, although a different medium is used so that a professional can easily differentiate between the work of the artist and the work of the conservator. The painting was then varnished to provide a protective layer against the pollutants in the environment. It also has the benefit of re-saturating the oils in the pigment layer and making the painting look better. Some of the staining was not removable without the possibility of causing abrasion to the paint layer. An aesthetic decision then had to be made as to whether or not the staining would be left visible or a light pigment wash applied to hide it. This photo shows the painting half way through the cleaning process with the tears, the hole and the residual staining still evident.

The next painting is by Elizabeth Parsons, Point Ormond, (Red Bluff) St.Kilda, 1881. Elizabeth Parsons, who was to become highly respected for her water-colours and lithographs, trained in England and Paris before moving to Melbourne with her family in 1870. The first public display of her work was at an exhibition of the Victorian Academy of Art here at the Library within seven months of her arrival. This particular painting is oil paint on artist's board, on the reverse of which is a hand-written ink on paper note by the artist taken from Lewis Carroll's The Walrus and the Carpenter

This work has been painted on a piece of artist's board that has been cut from a larger piece. Like Louis Buvelot, she was an early advocate of painting en plein air, and this use of small pieces of artist's board reflects the difficulty an artist faced in transporting all of their materials to their preferred outside position. The Heidelberg school later solved part of this problem by setting up a summer camp where artists could come and go and safely store their materials.

This painting was very dirty mainly through surface dirt and grime. There were large fly specks across the surface of the work; these are very acidic and will eat into the surface of the paint layer. Generally they are soluble in an alkaline solution but often they can be picked off with a scalpel which fortunately negates the need for alkaline surfactants. Again, not all of the staining was removable; some of the staining was left and some was disguised with a light wash of pigment.

The next painting is attributed to Reinhold Hofmann although the work is only signed R Hofmann and therefore it is supposition that they are the same person. Reinhold married and operated a bootmaking business in Toorak Road, South Yarra, in 1883–87 and it is probably in this period that he painted the two wonderful works in State Library of Victoria collection. Both works are titled Melbourne 1836 and show an early, elevated view of the Yarra River from the perspective of south of the Yarra. Included in this work are buildings and dwellings such as those of John Batman and John Pascoe Fawkner. There is a larger, more naive representation of the same image, which identifies the buildings from a numbered key. This larger work is on display in the Manuscripts room at the State Library of Victoria.

The Melbourne 1836 version now in the Cowen Gallery was originally oil paint on linen that has been lined onto masonite by an over-zealous restorer. Both surface dirt and an aged resinous varnish discoloured the surface of the work and hid the original colours. The image on page 42 shows the painting during cleaning and shows a white infilled loss area that needs to be inpainted to re-integrate the image. The finished painting has had all the discoloured varnish removed and the work has been re-varnished with a synthetic non-yellowing varnish. The loss area has been re-integrated by inpainting to match the original colour palette of the artist although, again, in a different medium to the artist to differentiate between the artist's work and that of the conservator.

Another very interesting painting in the collection is Princes Bridge 1892 by Alf Flood, who is thought to have had a stall as a cook at the Eastern Market in 1892 and lived at Gordon House in Little Bourke Street, Melbourne. This work depicts the single-span Princes Bridge that was replaced by the present bridge in 1873. It looks downriver from the South Yarra side of the bridge, through to ships at Queen's Wharf beyond. It also shows the boathouses on the South bank of the Yarra River and the workshop of the boatbuilder, Mr. James Edwards, who had run his business from the banks of the Yarra since the 1860's.

The painting had some quite serious flaking, most probably the result of water damage, which had dissolved the bond between the canvas, the gesso (a chalk/glue mix applied to the canvas to give an even surface on which to paint), and the paint layer. This had resulted in cracking and crazing across the surface of the work as well as the numerous small loss areas. The painting was also very dirty and covered with fly spots and accretions. The maple veneer frame had also been water damaged, and the veneer had fine shrinkage cracks, loss areas and was lifting across the bottom edge. The painting was surface cleaned using an alkaline solution. The fly specks were removed with a scalpel as were the accretions. The paint layer was consolidated so that the flaking was stabilised by re-establishing a fixative bond between the paint, the gesso and the canvas. The loss areas were infilled and inpainted to match the original paint and the painting was lightly varnished. The frame was also cleaned and consolidated using shellac to reform the bond. Again, loss areas were in-painted to match the original wood veneer. For the frame conservation and the general re-framing of all paintings after they were treated, I had the wonderful assistance of a specialist frame conservator, Amaia Itturi.

Framing of the paintings was somewhat problematic. Many paintings had lost their original frames and many of the original frames were very damaged. Michael Galimany, the Associate Curator who took over from Christine Downer on her departure, managed to reunite old paintings with their old frames, or to find old frames to fit old paintings. Sometimes, though, we just had to make new frames. In the majority of cases we had contemporary frames made in a variety of styles for those paintings with no frame history. However, some paintings warranted the construction of frames in their original style and we have some magnificent examples of craftsmanship in these extraordinary frames. The two major frames are in the red rotunda, which holds our colonial portraits. The two very large paintings which are on the farangled corners of the rotunda are of an early Governor, Sir Henry Barkly by Thomas Clark, and an early Premier, Sir John O'Shannassy by William Strutt. The gilt frames are approximately three metres by two metres in size and required three months each to make and five men and a hydraulic lifter to install. It must be said that their magnificence makes them worth the effort.

Another very interesting work is The Burial of Burke by William Strutt. In 1861, after the news of the death of Burke and Wills reached Melbourne, Strutt gathered eye-witness accounts and made preliminary studies for The Burial of Burke; one of these is a Study of Gum leaves that was exhibited at Bridget McDonnell Gallery in 1994. The State Library of Victoria's version of this painting is a large oil painting that was not completed until 1911, when Strutt was 86 years old. It had been re-framed but Christine Downer identified an inner slip frame that we felt was original to the painting. The aforementioned Study of Gum Leaves seems to have been used as a study for the canvas insert on the slip frame and therefore supports our theory on the slip frame. Unfortunately, we had no record of how the outer section of the frame would have looked. Due to the very rustic nature of the inner slip we chose a simple black moulding for the external frame which gives strength to the large work and does not detract from the visual richness of the painting.

There are many works still to be treated but stable enough to be hung in the Cowen Gallery until we have a new conservation laboratory. The painting Terrinallum Homestead by Louis Buvelot has had some unusual hands-on treatment in the past that has left the work very vulnerable to humidity problems. There are also large patches of oil paint applied by an overly enthusiastic restorer across the surface of the sky. The ethics of modern conservation allow us only to inpaint the immediate loss area in a different medium to the artist. (I use powder pigments in a modern varnish.) In the past, treatments involved much more intervention in a manner generally unsympathetic to the original nature of the work and this extensive use of overpaint, painted over the original oil paint, in oil paint, is a particular aggravation to the modern conservator. It is also a very difficult procedure to remove this given that you have to remove one layer of oil paint without disturbing the original layer. This requires patience, solvents, scalpels and a microscope and is one of the most demanding aspects of our profession.

The Buvelot painting is not the only one with this problem. The Ugo Catani painting, Collins St, Rainy Weather, has had the same overpaint problem across the surface of the sky area. I began treatment of this work using a solvent gel medium to help soften the thick layer of overpaint in the sky area. Sadly, when I removed this area of overpaint I discovered that the reason the work was repainted was because somebody had massively over-cleaned the painting and had seriously abraded the surface of the paint layer. This is one of the hazards when somebody attempts to treat a painting without proper training. It is also why, as professional conservators, we do not discuss the use of chemicals except in technical journals because we know the risks that they can cause to the artwork and to the person using them. Due to the extensive nature of the overpaint and the over-cleaning, it was decided not to continue with the treatment until we had a better equipped laboratory, which is due to be completed in 2006

One of the most important paintings still to be treated is the painting, Black Thursday, February 6th 1851, by William Strutt, which depicts one of the worst bushfires in Victoria's history, an event that resonates strongly with us all. An iconic painting of an Australian nightmare, the bushfire, it is one of the great treasures of the Library's picture collection, and there are few more significant works in the State's visual cultural archive. This painting has not been cleaned since it came into the State Library Collection in 1954 and we have found no record of cleaning prior to that. The painting was patched in the 1970s to repair a tear across the middle of the work. Again, this has been over-painted with oil paint and the treatment required to clean and conserve this work will be extensive and challenging.

I am indebted to Christine Downer and Michael Galimany for their detailed research on the Picture Collection.