Category Archives: Conservation

The Conservation of Poedua – Part 10

Hello everyone, we are back with our fortnightly updates on the treatment of John Webber’s Poedua.

We are progressing slowing with the cleaning of the painting.  At this stage, the cleaning involves the varnish removal and the removal of overpaints (later additions by a previous restorer).

The painting on the easel in the Paintings Conservation lab. You can see some areas where the varnish has been removed; the sky to the right of Poedua's arm and square patches in the tapa cloth. Photograph taken by Melanie Carlisle, 2011. © Te Papa

Today’s blog post will focus on one stage of the cleaning – the removal of the paper label which was attached to the face of the painting down in the bottom right corner.  This label may have been attached for a sale or an exhibition that the painting was once in.  The paper label had been completely saturated with varnish, which made it resistant to the aqueous solutions that we would normally use on paper.  Using the same solvent solution we have been utilising for the varnish removal, we drew as much of the varnish out of the paper as possible and then applied a methyl cellulose gel to soften the paper label which allowed it to be removed.

During the removal process. This image shows the paper label coated with a layer of methyl cellulose. The Mylar on top ensures the methyl cellulose does not 'dry-up'. Photograph taken by Melanie Carlisle, 2011. © Te Papa

We discovered that there were actually two paper labels, as well as the remnants of another, one on top of the other, which we managed to separate during the removal process.  We took great care to remove the labels whilst keeping them as intact as possible.  The paper remnants were removed first which revealed the topmost label.

The topmost label once the paper remnants had been removed revealing 36. Photograph taken by Melanie Carlisle, 2011. © Te Papa

The topmost label suffered a few small tears during the removal while the lowest remains completely intact.  We cannot disregard this type of information which may assist in research into the provenance of the painting.  The numbers 8 and 36 may correspond with a lot number at a sale or a listing number in the catalogue for an exhibition.

Once the first label was removed, this label was revealed with the number 8. Photograph taken by Melanie Carlisle, 2011. © Te Papa

 

So no matter how small, information like this is very important and care must be taken to retain it.  It would have been easier to remove these labels in a method which destroyed the information, but if we are doing our job thoroughly it’s not about choosing the easiest methods or getting the fastest result!

Isabel McIlraith – Textile Conservation Volunteer

This week we heard with sadness that Isabel McIlraith has passed away at the age of 104 years. For many years Isabel was one of a small band of volunteers working with Valerie Carson in the Conservation Unit, helping to care for the Te Papa textile collections.

She will be remembered here with gratitude not just for her work with the textiles, but also for her lively interest and optimism – and the lovely tussie mussies she would occasionally bring with her.

Gillian Andreae, Conservation – Object Support Manager

The Conservation of Poedua – part 9

Hello Poedua followers!  Mel and I have taken a break from our treatment of Poedua for a while in order to focus on some other paintings conservation commitments.
 
In the past two months we have been kept busy working on a loan of 23 paintings for the exhibition Painting New Zealand which is currently on display at Tauranga Art Gallery. 
 

We have prepared a number of paintings that have been on display in the Te Papa touring exhibition E Tu Ake, which will soon be making its international debut at the Quai Branly in Paris.

Lastly, but by no means least, we have also been very busy working on the upcoming Oceania exhibition which will be opening soon at Te Papa and City Gallery Wellington.  The Tony Fomison painting below is one of the many art works that will be on display in the Oceania exhibition which is on during the Rugby World Cup.

Te Puhi o te tai Haruru, 1984-85, Fomison, Tony (1939–1990), Auckland. Purchased 2003. Te Papa

Te Puhi o te tai Haruru, 1984-85, Fomison, Tony (1939–1990), Auckland. Purchased 2003. Te Papa

If you are missing your fortnightly Poedua updates, here are a couple of other conservation blogs that you may find of interest from some overseas colleagues. The first is written by Hannah Tempest who interned with us last year and is currently undertaking an internship at the National Gallery of Denmark in Copenhagen. The second is written by conservators at the National Gallery of Victoria in Melbourne and follows the conservation of a Nicolas Poussin painting.

The Conservation of Poedua – Part 8

If you have been following Mel and Katherine’s Poedua treatment blogs you may be surprised to read another’s voice on this one – a voice from the edge as it were. I’m Matthew O’Reilly, Framer of Paintings here at Te Papa. My previous blogs were quite some time ago now. Katherine and Mel have needed to take a short break from Poedua, so in order to keep the rhythm going I shall begin my contribution to the Poedua story (always intended) now. My first post on this subject presents a provisional view on the origins of the beautiful frame.

As will be plain from the accompanying photos a lot of remedial effort will be required for the frame to present the painting as befits its role; the conservation will be the subject of later posts. This post summarises the preliminary process.

From the time I first sighted Poedua in her frame the ensemble that they made excited me instinctively and aesthetically. The frame, like the painting, gives one a strong whiff of the Neo-classical period, with its strict rhythms of transverse elements of motif bounded with clarity by bright stepped bands, and gives its matching to the painting a special sense of period authenticity and authority; the aesthetics of its form and scale a sense of rightness as a means of carrying the painting and its subject forward through time. It helps to place her in history as well as any but the most clearly documented original framing: together they admirably represent the junction of the Enlightenment impulse that took Cook to the Pacific, the contemporary currency of Neo-classical style, and the incipient Romanticism symbolised by Webber’s subject.

Image of Poedua in its frame immediately after it arrived at Te Papa. Photograph taken by Michael Hall. © Te Papa.

Image of Poedua in its frame immediately after it arrived at Te Papa. Photograph taken by Michael Hall. © Te Papa.

The frame and its relationship to the painting. A hunt for clues.

In assessing treatment options for picture frames it is important that all possible evidence is gathered about their provenance as distinct from that about the paintings they contain, so that the best quality treatment decisions can be made — especially concerning appearance. Whether they mean to or not, picture frames play a critical role in representing context, which consequently makes them very important in the isolating milieu of the museum. It is very important that they serve their paintings well in this respect.

I am due to start on this frame’s treatment soon. As that proceeds more facts that go to a greater clarity about the frame’s relationship to the painting may or may not emerge, and curatorial research into the historical life of the painting may yet throw some light on just when it arrived on the painting.

To sum up the evidence so far gleaned from observation of the frame, research of available literature, and some opinions from colleagues across the globe, it is possible for me to say for sure only that the frame fits within the general period of the painting and has an aesthetic correspondence that resonates sympathetically with it, connecting it well to the period when the painting was made.

Yet Poedua is not the first painting this frame has protected and presented. It may have been put on Poedua when the painting was made, and could be ten or fifteen years older than the painting; or it may have arrived on it after its arrival in France. So far, I have been unable to determine clearly whether the frame is English or French, but it is likely to be one of these. And despite the sense of rightness, clear evidence about the conjunction of the frame and painting is not yet there.

The painting is known to have spent much of its life in France. Perhaps too much can be made of the frame’s French stylistic inheritance as evidence, even as it obliquely interprets the painting’s historical journey so well. I can’t claim to be able to pinpoint from the evidence of the frame itself where and when it was made but think there is enough evidence to support its continued pairing with the painting.

This is not to say that this is necessarily this painting’s first and only framing, but is to say that it could be, and we at Te Papa will treat it as if it were so. There follows a summary of the clues that the examination of frame has yielded so far to support the frame’s authenticity to the general period from which the painting comes, even if it was not the painting’s first frame. I do hope that time and further research will tell a more detailed story.

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A reminder here: the painting was made in London in 1785 or very close to it.

1. Style. The profile consists of two main components rising from the picture surface, the inner and larger in scale being a scotia or cove (C-curve) carved in relief with transverse motifs; and the outer and upper one, smaller in scale and ogee (S-curve) in form embellished with transverse carving in relief. This doubling effect of two layers of transverse motif separated by plain bands of gilding is the most striking element of this design of frame which would tend to limit the probability of its production to perhaps 1770 at earliest and 1810 at latest. The origin of the style lies in France, but its uptake into England was very quick and some more teasing out of the motifs themselves and how the carver has treated them is required to come to a strong opinion as to which country it comes from.

2. Materials and techniques. The frame is hand-carved and gilded onto red clay and gesso. Hand-carving means the relief ornamentation is cut out of the wood of the carcase of the frame members, and is not an enrichment made from plaster work and applied to the carcase. In statistical terms this fact increases the likelihood of an earlier rather than later dating, and is more likely to put it in the eighteenth century than the nineteenth. The thinness of the gesso layer of the original surfaces and lack of surface texturing may suggest an English origin. Against this however the use of some hard wood in the carcase seems to dispute this conclusion, and lean it towards France.

Upper left corner detail at the back showing cut-down mitre with remnant of original key plus later key across mitre. Photograph taken by Matthew O'Reilly. © Te Papa.

Upper left corner detail at the back showing cut-down mitre with remnant of original key plus later key across mitre; compare with upper right corner image. Photograph taken by Matthew O'Reilly. © Te Papa.

3. Historical alterations. There have been two clear interventions on this frame since it was first made. One of them in particular has some direct relevance to our search for understanding. That is, the frame has been cut down from its original dimensions. Occurrences such as this are remarkably common and come as no surprise. The painting itself does not appear to have been reduced in size, and is not one of a number of standard sizes that were common in Britain in the eighteenth and nineteenth centuries. The frame was cut down to fit a non-standard size painting, and so we can surmise that it was cut down for our painting. By examining the evidence of the carved corner motif on the front and the cross keys on the back used to strengthen the mitre joints, we know how much was cut from the two mitres and that the original frame aperture corresponded neither to the standard canvas sizes common in England or those (different ones) common in France. The other intervention to the appearance of the frame, involving a regilding of the outer sides, I shall return to in a later post as it does not bear on this discussion of authenticity and origin.

In our part of the world the sense of rightness of matching of painting and frame is all too rare and I delight in this occurrence of it.

The Conservation of Poedua – Part 7

In the paintings conservation lab, we have been working away steadily on the varnish removal of Poedua.  Every now-and-then we come across a painting where this stage of the treatment is relatively easy, where a simple organic solvent solution is effective in removing the varnish without any effect to any part of the underlying paint layer.  More often than not the treatment of varnish removal is more complicated and Poedua falls into this category!

There are many factors which make the treatment of varnish removal different for every painting that comes into the lab.  The materials and techniques of the artist are a contributing factor and with this painting the extremely thin paint layer and the use of glazes have resulted in the difficulties in the treatment.

The pale spots on the arm of Poedua are areas where the varnish has been removed. The exposed paint layer appears matte and dry and will be saturated again once the painting is revarnished. Photograph taken by Melanie Carlisle, 2011. © Te Papa.

More varnish removal test areas. The white hazy areas on some spots are caused by varnish residues remaining on the surface. This occurs when the solution does not work effectively at removing the entire varnish layer. Photograph taken by Melanie Carlisle, 2011. © Te Papa.

 Our initial testing identified some issues and we have had to stop and reassess our options and consider more complex cleaning strategies.  This is not unusual!  Varnish removals are the most complex treatments that paintings conservators perform and this is a part of our working process.  We begin with simple solutions and build up to something more complex when necessary.

Melanie cleaning a small test area in the drapery. Photograph taken by Katherine Campbell, 2011. © Te Papa

The same area after the varnish has been removed. Photograph taken by Katherine Campbell, 2011. © Te Papa

We have now formulated a method for removing the varnish layer from Poedua.  Our progress will be constantly monitored throughout the treatment.  It is a slow process, but the result will be worth all the time and effort.

The conservation of Poedua: part 6

Now that the painting has had its layer of surface dirt removed, the next step in the treatment is the removal of the varnish layer.  A lot of the principles that we talked about with surface cleaning, also apply to the removal of varnish layers.  Therefore, prior to beginning it’s important to establish as closely as possible what the varnish or coating is, consider whether it is appropriate to remove it and work out a strategy for removing it safely.
 

In the case of Poedua, we want to remove the varnish layer because it is very discoloured and has been applied extremely unevenly, which has become more apparent as the discolouration has progressed.  Similar to the effects of surface dirt, the discoloured varnish present has diminished the tonal ranges of the painting.  

 
Uneven varnish under UV

Under UV the uneven application of the varnish becomes really obvious. The bright green fluorescence indicates a natural resin varnish, 2011. Photograph by Mel Carlisle © Te Papa.

The first step is to characterise the varnish and work out how many layers are present.  There are several techniques available to us including, exposing the painting to ultraviolet light and taking cross-sections of the paint and varnish layers.  Looking at the painting under UV lamps causes specific auto-fluorescence in different materials which helps us with identification.  The varnish layer on Poedua fluoresced a bright green colour, indicating a natural resin such as dammar or mastic.  This wasn’t surprising to us since both are common varnishes that we might expect to find on a work such as this. 

Cross-section analysis involves the sampling of a microscopic piece of the painting, usually taken from an area of existing damage.  This sample is set in a polyester resin and ground down with fine sand paper.  The cross-section is then examined using a compound microscope where we can see the building up of paint layers by the artist, surface coatings and later additions.  From the cross-section we took from Poedua we can see that there is only one varnish layer apparent.

Viewing the cross-section under magnification

Once the cross-section has been prepared, we look at it under magnification and also UV to see the build-up of layers used by the artist, 2011. Photograph by Katherine Campbell © Te Papa.

 

Cross-section under UV and magnification

This a cross-section taken from a Don Driver painting in Te Papa's collection. 1980-0013-1; Zither; Don Driver. Under magnification and UV it's possible to see several layers of paint and 2 layers that fluoresce with the appearance of varnish. The cross-section was photographed by Sarah Hillary at the Auckland Art Gallery, 2010 © Te Papa.

Varnish layers become increasingly difficult to remove the older they are.  This is due to alterations in their chemical structure that occur over time.  The solvents that conservators use to remove varnishes are carefully tested in a similar manner to the surface cleaning testing.  We use a variety of solvent mixtures and different preparations and combinations including enzymes, soaps and gels.  Their effectiveness builds further on our knowledge about the varnish layer we are dealing with.  Solvents work by penetrating the varnish layer and swelling the film, bringing the resin into solution and allowing it to be removed from the surface.  After initial testing, we select the most appropriate solvent or solvent mixture and test this in the various areas of the composition.   Constant care and attention is crucial during this process because the varnish layer is usually the last layer before the paint film is encountered.

Testing the varnish solubility

Initial testing is done under magnification so we can closely monitor the results. As with the procedure for surface cleaning swabs are kept along with notes of the results for comparison, 2011. Photograph by Mel Carlisle © Te Papa.

 

Varnish removal tests

Once the pale paints have been tested we move onto all the major areas of colour. The two circular areas that appear dry and matt are the patches where the varnish has been removed and the paint layer is exposed. At the end of the treatment a new varnish layer will be applied which will resaturate and intensify the paint surface again, 2011. Photograph by Katherine Campbell © Te Papa.

The Conservation of Poedua: Part 5

In our last post we discussed the process of testing to identify the most appropriate cleaning solution to remove the surface dirt layer from the painting.

After finding the best cleaning solution for the painting the surface cleaning can begin, but we always carefully monitor our progress to ensure that the cleaning solution is working effectively without any adverse effects for the painting.

We generally begin in the lighter areas of the composition, because we can see the progress best in these areas and it allows us to get a feel for the action of our cleaning solution.  We hand-roll cotton wool swabs on bamboo sticks and slightly dampen the swabs with the cleaning solution.  The damp swabs are rolled across the surface of the painting and the dirt is lifted and removed from the surface.  We stop rolling the swab once it appears dirty.  We don’t want to roll the dirty swab across the surface because the particles which collect on the swab may be abrasive.  Because this painting is so dirty we had to change our swabs quite regularly!

Here are some nice photos to show you the progress of the surface clean.  You can see the difference that removing this layer has on the colours, tone and depth in the painting.

We begin by expanding our test areas. This rectangle is the first area of the painting to be cleaned. Photograph taken by Melanie Carlisle. © Te Papa.

 

We continue by expanding the rectangle. The removal of the surface dirt layer is revealing the depth in the composition. Photograph taken by Melanie Carlisle, 2011. © Te Papa

 

The cotton wool swabs are changed after a few rolls across the surface. We filled three jars of swabs completing this treatment. Photograph by Melanie Carlisle, 2011. © Te Papa

 

Katherine and I working on the painting. Photograph taken by James Kirk, 2011. © Te Papa.

Cleaning progressed from right to left. In this detail the difference between the dirty and the cleaned sections is distinct. Photograph taken by Katherine Campbell, 2011. © Te Papa.

 

The cleaning is almost there! The top left of this detail is all that remains of the surface dirt layer. Photograph taken by Melanie Carlisle, 2011. © Te Papa.

Katherine works cleaning the top left corner. Photograph taken by Melanie Carlisle, 2011. © Te Papa.

 

The painting after the surface cleaning. The varnish layer still hides the true colours and tones, but already we see a great improvement. Photograph by Melanie Carlisle, 2011. © Te Papa.

There has been a significant change in the appearance of the painting and Poedua is looking much better already!  The removal of the surface dirt layer has revealed the varnish layer beneath it.  The varnish is yellow, discoloured and uneven.  The next stage of the treatment is to remove this varnish layer.  This is the most complicated stage of the treatment.

Preparing garments for display – the tricks of the trade

We are currently in the throes of preparing for our upcoming exhibition  New Zealand in Vogue, which opens in the Eyelights Gallery on 24 June. The exhibition is inspired by the decade during which New Zealand had its very own Vogue magazine – 1957 to 1968.  The exhibition features garments and accessories by New Zealand designers and manufacturers whose creations regularly graced the pages of Vogue New Zealand. Currently, the garments are being prepared by our Textile Conservator, Anne Peranteau, for photography and display.

The garments are being exhibited on ‘standard’ dress forms, ranging in sizes 10 to 14. However, as most women know, there is no such thing as a ‘standard’ size. What might fit beautifully across the bust, might gap or pull at the back. What sits snugly at the waist, might fall off the shoulders and so on. While women use a range of tricks, from highly engineered foundation garments to plastic surgery, to force their bodies to conform to fashion’s changing ideals, Anne Peranteau is applying similar tricks of the trade to our dress forms in order to bring back to life the figures of the women who once wore these garments.

Anne has been busy enhancing bust lines, and happily fabricating bulges for all the ‘wrong’ places – ensuring that our perfect forms have the tummies, hips and curvy derrière synonymous with an hour glass figure. I will now hand you over to Anne, for an insight into how she does it!

Mannequins with dressing sheets

 The garments in the exhibition date from 1957 to 1968, a period characterised by the lingering influence of Christian Dior’s New Look.  The so-called H line featured fitted bodice and full skirt flaring from a drawn-in with a broad shouldered jacket. 

Some garments requiring a special shape are exhibited at Te Papa on custom forms, sculpted of archival polyethylene foam.  Such is the case with the 18th century silk brocade bodice currently displayed in Enriching Fashion. The carved form made for the bodice enables the displayed garment to assume the conical shape that it would it would have had on the body, due to the corset worn underneath it.  Each custom form takes days to construct however, so the 19 dresses in the New Zealand in Vogue exhibition will be displayed on standard Purfex forms, modified to adopt the silhouette of late 1950’s and early 1960’s fashions. 

The mannequins are typically fitted to each garment based on the waist measurement, but because the mannequins have a quite contemporary shape, the bust and hips usually need to be augmented for the 1950’s era dress to fit properly.  Even the relatively simple chemise dresses of the 1960’s had a differently shaped body underneath, keeping in mind what was imparted by period undergarments (for example, contrast the shape of the bust created by this 1950’s brassiere, Fig. 2, with the bust of the contemporary mannequin).

Bra by Berlei (N.Z.) Limited, 1950 - 1959. Purchased 2003. Collection of Te Papa.

Bra by Berlei (N.Z.) Limited, 1950 – 1959. Purchased 2003. Collection of Te Papa.

It is important to be observant of the clues given by the garments themselves. One of the dresses in the New Zealand in Vogue exhibition is a lively peacock blue cocktail gown that was worn by the museum’s previous textile conservator, Valerie Carson, for a birthday in 1957.  The party was particularly special as it doubled as her engagement party.

The bodice of the gown flares slightly from the waist; this shape is accentuated by the wide neckline.  Bodice front and sleeves are cut from a single piece of fabric.  The full skirt is stiffened with Vilene interfacing and the waist is kept pulled in with assistance from an elasticated fastening on the interior. 

When I put the dress on its size 10 form[1] (see below), several things indicated what adjustments needed to be made to the mannequin:

  •  the waist of dress fell a few centimeters below natural waist
  • there was far too much ease, or gapping, in the bodice on all sides, making it difficult to appreciate its flared shape.
  •  the fullness of the skirt was falling in deep folds around the mannequin pole, with buckling around shaping darts, creating an overall impression of something wilted.

    Dress by Polly Peck, 1957. Gift of Valerie Carson. Collection of Te Papa.

Looking a little wilted.

 

To address each of these issues, the following steps were taken:

  • Shoulders were made of rigid Ethafoam archival foam.  The foam was covered with washed knit fabric and attached to the mannequin torso with stitched Velcro attachments.  Attachment of the shoulders enabled the  dress to be supported at the right height and brought the waist of the garment in line with the waist of the mannequin
  • The mannequin was padded out across the back, hips and bust with archival heat bonded Dacron polyester (image below). 

Compared to the adhesive bonded variety of padding, this type is safer for the objects on long term display.  The Dacron padding is readily shaped to approximate the appropriate anatomical features.  When dressing body-clinging knits and tight fitting garments, it is helpful to tear rather than cut the Dacron, to prevent the edges of the padding from being visible under the garment. The padding is inserted underneath the slipcover, which we have made from a pair of nylon stockings (XL, and do not use control-top!). and secured to the mannequin with woven tape stitched at centre front and centre back of the waistband.   Once the padding out is completed it is sometimes necessary to cover the whole assembly with a show cover to keep everything tidy and invisible. 

Mannequin padded out with Dacron.

Mannequin padded out with Dacron.

  • A bespoke cotton and tulle petticoat, made by volunteer Dorothy Bradey, was used to create the proper flared shape in the skirt of the dress (the original underskirt is not in the museum’s collection).  Period undergarments are sometimes be used when dressing mannequins, but particularly for older items of historic dress, reproductions (or unregistered “props”) are preferable because of concerns regarding the strain placed on bustles, cage crinolines, and similar items when supporting garments.

 The appearance of the dress at this stage can be seen in the final garment, now ready for photography and display.

Dress ready for display!

Dress ready for display!

Finally, just a word about conservation.  The process of putting a garment on a mannequin can place momentary but significant strain on seams and fabrics.   Getting the waist seam of a extremely fitted garment past the shoulders and bust of a fiberglass mannequin is a completely different experience than getting it on a flexible, fleshy body.   Once a dress is on a mannequin the shoulder areas and waistbands or waist seams usually bear most of the weight of the garment, and they do so continually over the length of an exhibition.  Before beginning the dressing process, careful condition checks are done to make sure that each dress can withstand this.  Fastenings are also checked to make sure they are secure and functional, and if not, it must be determined whether they can be replaced.  Conservation treatments may be carried out to reduce staining, stabilise weak areas and generally make the costume safe for long term exhibition.

Anne Peranteau, Textile Conservator


[1] Purfex mannequins (model FORM001) were used.

The Conservation of Poedua: Part 4

Now that we have cleaned the back of the canvas we can look at surface cleaning the front of the painting.  This is a separate procedure from the removal of varnish and overpaints and is completed first because surface dirt is the first layer encountered.  The reason we remove the dirt layer on paintings is because it considerably alters the colour and tone of original paint, can obscure image detail and significantly alter the surface gloss, clarity and hue of surface coatings.

Surface Cleaning

Detail; 1992-0035-1883; Lake Manapouri; Baker, William George; During treatment. The cleaned rectangular area at the left shows you what a difference surface cleaning makes to the appearance of a painting, 2006. Photograph by Katherine Campbell © Te Papa

Surface dirt is a mixture of all sorts of quite unpleasant things including flakes of skin and hair, smoke from household fires and tar from cigarettes, food and drink deposits, moulds and fungi, insect debris and general atmospheric pollutants!  To remove the surface dirt, it is necessary to overcome the bonds that are holding the dirt to the painting without disrupting the underlying paint layer.  To find the safest cleaning formulation we carry out a process of testing different mixtures through careful application and monitoring of the results.
Testing notes

As we go through the testing process to find the best cleaning formulation, we keep a detailed written record of what we used and how well it worked, 2011. Photograph by Katherine Campbell. © Te Papa

When we carry out our testing, we apply the cleaning solutions with small cotton swabs in a rolling motion over the paint surface.  We test inconspicuous areas first, starting with light colours and then progress to all the main paint colours.  We keep and label the test swabs for comparison.  We often have to reassess our cleaning strategy because the solubility of dirt and paint can change across the surface of the painting requiring the use of different materials and concentrations of solutions. The most common surface cleaning agents are aqueous in nature – meaning they are water-based.  We can modify and control the properties of the water by adding pH buffers and ionic buffers and by adding chelating agents, surfactants, enzymes and gelling agents.

Mel mixing

Mel carefully makes up a testing solution to trial on the painting, 2011. Photograph by Katherine Campbell. © Te Papa

Last year I was able to attend a course in Melbourne about the cleaning of paintings using the Modular Cleaning Program.  This is a database system and an approach for cleaning paintings that has been developed to help conservators use established theory and materials in a way which makes the complicated chemistry of cleaning more accessible.  Basically, the computer program is better at working with piles of numbers than us!  It saves us time by working out the complicated stuff, like ionic equilibria, which requires pages of calculations and is really boring and not to mention, tough!

MCP

With the help of the modular cleaning program, we are able to make up and test a wider range of formulations than we would ordinarily have time to do, 2011. Photograph by Mel Carlisle. © Te Papa

Through our testing and the help of the Modular Cleaning Program, we arrived at a solution containing a mixture of enzymes which we will use to safely and effectively surface clean Poedua.  The next blog post will talk about the surface cleaning process now that we have found our cleaning agent and will include some nice images of the cleaning in progress. 

spliced image

Once a suitable cleaning formulation has been found, all the paint colours utilised in the composition are tested to make sure of its suitability. The small circular areas are the cleaned test patches, 2011. Photograph by Katherine Campbell © Te Papa

The Conservation of Poedua – Part 3

After completing our technical examination of the painting, taking lots of pre-treatment photographs and writing the condition report, we write a treatment proposal for the painting.  We consider the current condition of the painting and what we would like to achieve with different treatments.  Our proposal is discussed with the curator and together we outline the aims and objectives of the treatment.  No cleaning of a painting is without risk so all options need to be discussed.

The treatment schedule for Poedua begins with surface cleaning the reverse of the painting.  Methods of surface cleaning fall into one of two categories; Dry, where brushes, tweezers, erasers and/or sponges are used to lift and remove surface dirt from the surface; or Wet, where aqueous solutions, solvents or gels are used to lift and remove the surface dirt.  Generally for paintings on canvas we begin with cleaning the reverse of the painting using dry surface cleaning methods.

For Poedua the cleaning of the reverse of the canvas occurred in a number of stages.  It began all the way back in November when the painting was still in London.  To prepare the painting for travel, dust and debris were removed from the area between the canvas and the bottom stretcher member.  This was removed because the pieces could have moved around during transit and caused damage.

 

A pile of dust removed in London before the transit of the painting. The debris included straw fragments and an old nail. Photograph by Melanie Carlisle, 2010. © Te Papa

Forward a few months and the painting is in the conservation lab.  We carefully lay the painting face down onto a clean table and use a brush and an indirect vacuum (holding a vacuum on low power above the canvas rather than touching the canvas with the vacuum) to remove the loose dust and dirt particles.  

Dusting the reverse of the canvas with a brush and indirect vacuum. Photograph taken by Katherine Campbell, 2011. © Te Papa

This was only partly successful so we cleaned further using small pieces of dry cleaning sponge to lift dirt that was caught in the interstices of the canvas weave.

Katherine cleans the reverse of the canvas with a dry cleaning sponge. Photograph by Melanie Carlisle, 2011. © Te Papa

Finally we removed more dust and debris which was caught between the canvas and the bottom stretcher member.  It was impossible to complete this part of the treatment in London because of the restrictions of materials, time and place.  We held the painting up at the bottom edge and left the top edge resting on the table to allow the dust and debris to fall away from the painting.  We used a variety of tools to carefully remove as much as possible from this area.   

As I hold the painting, Katherine uses a palette knife to gently dislodge dust and debris caught between the stretcher member and the canvas. A pile of dust can be seen on the table top. Photograph by Matthew O'Reilly, 2011. © Te Papa

Our treatment of surface cleaning the reverse of the canvas has resulted in the inscription being clearer and easier to read.

In the centre of this photo the canvas has a grey appearance where it is yet to be cleaned. The P of Poedua has been cleaned and is clearer and easier to read. Photograph by Katherine Campbell, 2011. © Te Papa

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