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Door to store: Caring for your watercolours and paintings

Vicki Humphrey, National Museum of Australia, 15 November 2013

VICKI HUMPHREY: Welcome everybody to today’s door to store. Today we are talking about watercolours and paintings. What I want to do to start with is look at the similarities and differences between these types of items, because I think, gives you a better insight into how to care for them. There are quite a lot of similarities but there are really significant differences in them as well. The aim of today’s session is to provide you with a better understanding of what these things are and also to get a good understanding of the types of problems that can affect them and the types of damage that they are vulnerable to - then in that way you are better able to understand how to care for them.

We will start with watercolours. The term ‘watercolour’ can refer to a technique of painting; it can also refer to the medium, which is the paint; and it can also refer to the object, a watercolour, similar to this one. Basically watercolours are made up of generally the support. The support refers to the thing that the image is painted onto so in the case of watercolours that is most often paper, but it can also be vellum. In the case of botanical illustrations a lot of artists use vellum. There are a number of other supports that are used. I am going to deal mainly with paper because that is the most common one that you will come across.

Then you have the paint itself. With the paint we are dealing with quite traditional materials. Watercolour painting is quite old and dates back many centuries, probably right through to some of the cave paintings which may have had a watercolour medium. The watercolour paint is made up of a pigment, a binder, and the binder is generally gum arabic which is a gum sourced from acacia trees. They have also in the past used honey, sugar and various things like that - something that is fairly light, water soluble and will dry and hold the pigment to the paper. There are other things that have been put into watercolours but basically they are the main components of a watercolour paint. Watercolour paint is essentially transparent. It does not have an opaque pigment in it. When it has opaque pigment in it, something like lead white or titanium white, it is called body colour or gouache , and gouache tends to be a bigger pigment granule, along with the opaque paint.

When we are looking at paper, the support, we are looking at a material that is organic. It’s made from cellulose. It’s made up of a lot of cellulose fibres mashed up and processed in a way that we get individual fibres. To make paper you have about five per cent paper fibre, 95 per cent water and it’s basically a felting process. A mould is pulled through the water in the traditional paper-making technique, the fibres rest on the mould, the water drains away and you have a sheet of paper. That has obviously become mechanised and mass produced, but the principle is basically that.

Paper is then sized so that it doesn’t remain like blotting paper and so it can take ink. Specialty watercolour paper is manufactured so that it has a bit of absorbency but it is stable in water. If you get a piece of photocopy paper or printing paper and you get a paint brush and brush on water, you will find that the paper will cockle. That is the distortion that we get when it has moisture on it. Watercolour paper doesn’t do that, so it’s actually especially made for watercolour painting.

One of the things about paper is that in traditional paper making it was made with fibres that had quite a lot of stability chemically. More modern papers tend to be made from cheaper fibres and are much more mass produced. Once they introduced chemical bleaches and different sizes to paper, we got a lot more deterioration. From the Industrial Revolution on we have still had good quality paper but the bulk of the paper that we use everyday is a much poorer quality than the older traditional papers. So there is an inherent weakness in some of the papers that we come across there.

We have also got the pigments and the binders in the watercolour medium that can cause problems. I will talk about that a little bit later when we come to look at the types of problems we have.

Looking at paintings, in many ways we are looking at a very different type of object. A painting is a much more complex structure. In some ways I would say there is probably a lot more variations in paintings - we still have a support but we have multiple layers in a painting.

The supports in paintings traditionally have been a board, and often a timber board, or the one that I think most people are very familiar with is a linen canvas. There are lots of variations on this, particularly in modern times where people are painting on Masonite. I have one here which is painted on Masonite. When I examine this painting quite closely I know that because I can see the texture of the Masonite underneath the paint layer. We have a huge number of variations. Given that, I am going to concentrate on the most common ones we come across, and that will be the canvas.

When we have a painting on canvas, we have the canvas layer and then on top of that there is a priming layer. The priming layer is put on there to stabilise and also to create a smooth layer on which the paint can be applied. If we didn’t have the priming layer, and there are sometimes a number of layers before the paint is put on there, if we don’t have that we get the texture of the canvas. So in some paintings where you have very delicate detail, that would interrupt the aesthetic of the painting. There can be sometimes a couple of layers of those. That traditionally is something like a chip wide . That is applied with a white pigment usually in a rabbit skin glue, again quite traditional materials, although more recently we are getting acrylic grounding layers.

After that you have your painting layer. In the case of something like this one, that can be a fairly flat surface paint applied to the surface or, in the case of this one here, we have very deep layers of paint and paint protruding from the surface. That is very important. That’s a technique called impasto which creates a real texture in the painting but if on canvas it can also have some issues in terms of the thickness of the paint and how that might behave.

On top of that, you generally have a varnish layer. The varnish creates a surface that allows the light to reflect in a certain way. It deepens the colour. Without the varnish layer, the colour doesn’t appear as bright, as vivid. The varnish layer also smooths out some of the imperfections in the paint layer. There is not always a varnish layer. A number of modern paintings are very deliberately very matt and they don’t necessarily have a varnish layer. They may have a matt varnish but they have significant problems in terms of conservation because of that matt surface that can be quite problematic to deal with.

On this painting we have a small area that has no varnish on, and it probably won’t be picked up by the camera, I suspect. Down in this little area, there is an area that is dull, that doesn’t have a sheen, and it’s quite a different surface. One of the things that happens with the varnish layer is that it can very much discolour. You see in accounts of restoration and conservation of old masters, and particularly things like the ceiling on the Sistine Chapel, a real difference once the deteriorated and discoloured varnish is taken away and replaced by a new varnish.

In addition, paintings can also have glazes. Glazes can be coloured additions over the varnish or within the varnish layer or on top of the varnish and before another varnish is put on, depending on the technique the artist is using, that add depth and three-dimensional feeling to the painting. It can also add very subtle hints of colour and, because it’s separated and on top of the painting, it really enhances the aesthetic. They can be very complex pieces of art. In terms of the technicality of them and in looking at them and examining them and knowing how to conserve them, many paintings can quite difficult to work on. A lot of research has to go into them. Equally with watercolours, a conservator looking at a watercolour has to really understand what the watercolour is about, what techniques have been used, what pigments are there and the sorts of paper that has been used et cetera.

That’s why for any work on paintings and watercolours I would always advise, if you are going down the track of doing other than basic preservation, you get a conservator’s advice and also get a conservator to treat it for you. But there’s a lot you can do to look after these things yourself.

I want to look at some of the types of damage that you can come across with both of these items, the sorts of things that are problems. We have some really good examples on the table here. Conservators are always talking about relative humidity, temperature and light - we are going to talk about them again because they are really important in terms of how you care for things.

The principal damage you get with any cultural heritage material is physical and chemical, and often both in combination. The physical is fairly obvious in many cases, and I think this is a really lovely example of some of the typical physical damages you get on paper. You can see around the edges we have a lot of missing areas, we have tears, we have dog ears, we have these folded bits - lots of tears throughout.

Now I am not wearing gloves. I am going to make a note on that. Gloves are important to wear if you are handling things as they prevent oils from your hands getting onto items. Equally, when conservators are working on items, they obvious do not wear gloves. For a conservator working on something, particularly where you have paper that might be brittle or delicate, it’s really important that we can feel what we are doing.

Cotton gloves were very popular for handling paper. There has been a lot of talk about gloves or no gloves in libraries. Cotton gloves can actually prevent you having the sensitivity of feel that you need to uncurl curled paper, brittle paper, et cetera. I do have a box of gloves here and I would say if you are going to handle works of art, nitrile gloves are very good because they do prevent oils getting onto objects and this is really important when you are dealing with metals. We get a lot of questions about gloves or no gloves so I think that’s an important one to add.

Just on this particular item, we have a lot of physical damage but I said that the physical and the chemical are often interrelated. There is a number of areas here where we can see discolouration, and particularly around the edge there is a darker brown discolouration. That to me indicates that the paper has been affected by light or by contact with an acidic mount, and that has caused that to become acidic. Looking at the structure of paper - I am going to use this as a little example - this is a paper fibre, so it’s a big cellulose fibre. They are long strings and, when they are in touch with an acidic board, the acids can migrate into the paper. If it’s a poor quality paper, contact with light falling onto to it, UV light particularly, can set up a chemical reaction which breaks the fibres so basically the fibres get shorter. When you have a felt of lots of fibres that are interlinking and are held together by what we call hydrogen bonds between the fibres, as these fibres get shorter, your felt loses strength - the strength in the paper goes - so we start to get brittle paper. This is very typically illustrated by newspapers that have been left out in the sun or old newspapers that you might find in your home. You can pick them up and bits just flake off. That is very indicative of that chemical damage to the paper fibres. So that chemical damage has led to some of these pieces falling off. There is a combination here in poor handling - I can see creases, et cetera - but also of chemical damage leading to problems with the paper.

On this little watercolour, although is a mixed media because we have some strong white here, you can see these little brown spots all the way through. You often see these on paper items and on watercolours - it’s called foxing and that’s based on the colour of the stain. It’s thought that foxing is caused by mould in paper. There have also been theories that it’s caused by little tiny fragments of metal that have come from the paper making process. There are also theories it’s a combination of the two. With foxing it can be treated.

One of the problems with treating foxing is that it’s a bleaching process, and bleaching can cause damage to paper because it’s quite a severe chemical treatment. The other thing about it is that it can be quite an expensive treatment because we have to treat every individual spot with the bleach. Many conservators are using milder bleaches these days if they are bleaching, but often we get the decision not to do anything at all with these sorts of things. So that’s quite a common thing you will see in watercolours.

One of the things about watercolours is that generally you don’t have white. You don’t use a white pigment because, as I say, that then becomes a mixed media. So the white in a watercolour is generally the paper showing through, and watercolour artists use the texture of the paper and the behaviour of the pigments to create certain effects. In this area in the sky, and this is very typical on watercolours, this is not white. Now the paper may not be absolutely pure white to start with. It may not be what we see in modern paper as being very, very white but generally watercolour paper is pretty white. In this case we have discolouration, and that could have been caused by a number of things. It’s often caused by exposure to light so that if something is in a frame, it’s displayed for a long period of time, the light with UV components falls on it, sets up a chemical reaction and it starts to discolour. That can also cause fading of the pigments.

I don’t have a good example of fading of pigments here at the moment, but in many cases we take watercolours out of frames and we will see very strong colours around the edges where it’s been covered up by the mount and in the middle it’s much paler. This is very typical and a really good lesson in not exposing things to UV and to direct sunlight because that cannot be reversed.

This discolouration here is quite typical. The darker discolouration that appears on some of these areas may be because of exposure to light. It may also be something that is in the paper. Some of these deterioration reactions can be quite complex.

I am just going to talk about deterioration to paintings before coming back to some of these as well. We have some really good examples here of problems with paintings, and it’s mainly on this little fellow here. At the bottom of this painting - I am going to hold it up like this - we have a lot of loss of paint along there. We believe that this was in a situation where the bottom of the painting got wet and remained wet for a period of time so that the various layers that I have described - the primer layer, the ground layer and the paint layer - have started to delaminate. There are a number of different ways that these things can delaminate, and one of them is movement of the canvas. If the canvas is handled badly, if it moves with fluctuations in relative humidity, we can get the delamination. That’s a really good example.

We have a lovely little hole here that I will try to illuminate - you can just see it, I think – that is actually a puncture hole. It’s surprising how often paintings can get damaged by broom handles and various other things as people walk past not realising how far their broom handle or their backpack or whatever extends and bashing into the painting. That is a real dent in the painting and has broken through all layers. That’s an awareness issue that people have to be very careful.

We also have another little piece down here, which hopefully we can show, where we have lost all layers except for the canvas. From where I stand here I can see the threads of the canvas where all the layers on top of the canvas have gone away. That would not necessarily have been due to the same causes where we had the delamination down here. This is probably more likely movement in the canvas at some time or some sort of nick in the canvas.

I touched on relative humidity and the movements that can cause problems with the canvas. Fluctuations in relative humidity are one of the key things that can cause problems for both watercolours and paintings, particularly paintings where the standard way that we mount canvases is to put them on a wooden frame, a stretcher or a strainer. There is a difference between a stretcher and a strainer.

If we look at the top half of this painting, a strainer is like that - it has nothing in the corners there that mean you can adjust the canvas. So that remains at a certain tension, and when we get changes in relative humidity, timber and canvas react differently to relative humidity. Timber will expand and contract with changes in relative humidity, as will the canvas, but they will do them at different rates both because they are different materials but also the thickness of the materials involved. In certain conditions we can get the canvas becoming very floppy, and this is not very taut canvas. If the canvas becomes floppy, it’s much more likely that the paint layers and the ground layers will start to delaminate and have the potential for paint loss.

A stretcher has keys in the corner, and that is an example of a key just there. That allows a conservator on an ongoing basis to adjust the tension in the canvas so that we don’t have the canvas getting floppy which means that, if we do experience fluctuations, we can make the adjustment. Ideally we don’t experience the fluctuations or certainly not rapid ones.

With paintings, the changes in relative humidity will change those physical dimensional changes, and that can happen with watercolours as well. I will show you how we generally mount watercolours to try to prevent some of those things happening. If a watercolour is stuck down to a backing board, which we often find some framers in the past have done and some in the present will actually stick things down to backing boards, what happens then is you have a differential reaction in the same way as the canvas and the timber to changes in relative humidity. Sometimes you will see watercolours that are bowing like that, and there is an additional layer of the glue there and they all react differently so they will have a dimensional change. Sometimes – though rarely - we do see things that get split because of that change.

The other big one in terms of relative humidity for both paintings and watercolours is that above 60 per cent relative humidity you are likely to get mould growth, and mould digests the thing it’s growing on. It’s basically sitting there eating away at what is underneath. Mould growth on paper can be really damaging. In fact, you can actually lose the strength in the paper and really end up with just a pulp in the area where the mould is growing. It’s extremely damaging to paintings as well, but perhaps you have a little bit more time once you get some mould growth on a painting rather than on a watercolour.

I want to go back to light again, because again we have something in common with both paintings and paper in that light will affect the pigments. It will cause fading and it will cause discolouration. Paintings are considered a bit more stable than watercolours because they also have that varnish layer and the binder that the pigments are in in the paintings is a much more robust material. I haven’t mentioned that so I will just talk about that quickly.

The binder for the pigments in paintings is, in the case of oil paintings, basically like a linseed oil - a bit like what you put on cricket bats - and it’s called a drying oil. It dries by evaporation but it is a very complex polymer and it has a chemical reaction as it dries, which means that it forms a varnish in fact. It creates a layer that is hard and protective. The gum arabic does the same but it’s much lighter and remains more soluble. It will remain water soluble for a long time, whereas this is not water soluble to start with and becomes less soluble, and as it ages becomes less soluble in all sorts of organic solvents that we might use.

So what you can you do to look after your own watercolours and paintings?

I hate saying it but it always comes down to housekeeping. Housekeeping is vitally important. Keeping things clean is really important. Dusty storage areas aren’t just dirty and dusty, they also attract insects. High relative humidity and dirt really attracts insects - they love it. For paper-based items, silver fish are one of the key insect pests that cause damage, and they like nothing better than dark pokey spaces with lots of dust. A significant percentage of dust is human skin flakes - not nice, but it’s true, and that’s a lovely little bit of protein for insects to hang around and eat. They also like to eat paper. We have a lot of cellulose in here - we are basically talking about food. This is food. You will find on some objects that some insects will actually eat particular types of pigment areas or bits that have particular binders in them so you can get grazing. I don’t know if you have ever left something with a label on out in the garden and seen what the snails do to it. That’s probably got a starch in it and they just love going through and having a chew on that. You really have to keep things tidy and clean.

You need to minimise the fluctuations in relative humidity. That’s not always easy to control. Even the best air conditioning systems have difficulties in maintaining a flat-line relative humidity, particularly with temperature changes on the outside. One of the things you can do is buffer things by putting things in layers of protection. For example, if you are not displaying your watercolours, a box like this is a really good way to store them. In a lot of organisations, including here at the National Museum of Australia, we keep things in standard-sized mounts and we are able to then put them in standard-sized boxes. And then we have a really good buffer against changes in relative humidity in the storage region. The relative humidity here and the temperature here will be quite different to what’s in that box and what the items are subjected to, because you have an absorbent material here in the box and then you’ve got layers and layers of absorbent material with the mount board. So everything is buffered against the relative humidity.

The other thing is that, if you are not displaying things, it’s really good to get them out of the light. Once the chemical damage caused by light starts to happen, it’s irreversible and will continue to happen, but we can slow it down. Basically conservators in the business of looking after cultural heritage are not performing miracles. We are just slowing down the rate of change to try to keep things longer.

For paintings, there’s a lot you can do for paintings and a lot of it is about how you handle them. I am going to turn this one around just to demonstrate some do’s and don’ts. When you are handling a painting, never put your fingers underneath that. Try to stay away from that area because you can actually distort the canvas but you can also then stretch it a little bit so that you get more dirt and insect activity inside.

When we put canvases on display and also when we travel them, we try to have a backing board on them. We use a light archival material and we attach the backing board to the stretcher or strainer so that that will prevent dirt getting in there but it also reduces the risks of insects getting in there and it protects the back of the canvas from impact. So that’s a really good way to do it. I would suggest that it’s worth getting a conservator to do, but it’s a really nice way to do it.

The other thing is when we are putting them on to stretchers - this is a really difficult one to see because this is a work in progress – is that the stretchers we use usually have a bevelled edge in here. You often see paintings where you look at them and you can see on the front of the painting the edge of the stretcher or strainer showing through. So we use ones with a bevelled edge so that we are not getting that impact. The other thing we can do is once we have the backing board on put handling straps there so you are not handling the canvas directly but you have straps there that allow you to lift it. If you have a large painting – or anything really but particularly large items – then plan your movement. If you are going to move it from one place to another, make sure you have enough people to lift it. It’s not just about looking after your own self manual handling aspects of the job but also looking at making sure that you have enough people to lift the items so that you are not going to drop it. You should plan your movements so that you know where you are taking it to is clear and you have somewhere to place it. When you do move it and if you have to stand it against a wall, it’s always a good idea with framed items to stand them on blocks. Prepare some wooden blocks, stand them on blocks. Then if there is something spilt near them, they are not going to get the immediate effects of that, unless you have a big flood coming through. But if you have them on blocks, you have your frame and your item protected.

Framing watercolours and mounting watercolours - I spoke about the way that if watercolours are stuck down they can distort because of the differential movement between the backing board and the watercolour. So what we do is we tend to hinge them. This will probably be quite difficult to see but just to let you see this - that little item is not stuck to a backing board. We are allowing that to move as it naturally will with changes in relative humidity or temperature. It’s hinged. It has a T hinge running vertically that’s stuck to the back of the item. It’s a Japanese paper, and you can actually buy Japanese paper that is already gummed with an archival gum so you don’t have to prepare your own. It can be bought. Basically what we do is we try to tear the edges so that they don’t create a hard edge on your work. It’s one that way and then we don’t stick the work to the board, we use the top of the hinge and put a T hinge across at the top of the T so that holds the thing in place.

On either side of this we have an archival mount board. This is a board that is of high quality paper pulp, that will not discolour and that will not cause acids to migrate into the work. We have a window mat that is hinged to the backing board, not stuck down to the backing board, so that allows us to actually get to it and do what we need to do if there are some adjustments to be made or if we need to condition check it and see that it’s stable.

A mount has a bevel. You will pretty much always see a bevel on the mount. That is generally an aesthetic thing because, when items are on display, that bevel doesn’t cast shadows on the work. That’s a really important thing. But the window mount performs a really important function in terms of preservation. Here we have a little watercolour that’s framed and the watercolour is against the glass. It doesn’t have a window mount and it doesn’t have a spacer between the item and the frame. That can cause real problems because, if you get changes in relative humidity, you can get condensation inside the frame. That condensation can either promote mould growth or can cause colours to run if the watercolour is still soluble. I have seen instances of photographs stuck to the glass where we just could not separate them. It is unlikely to happen with a watercolour that it will become permanently stuck, but you can certainly have loss of image because some of the colour can stick to the glass. It’s really important in terms of looking after watercolours and anything that is framed with glass that you have a spacer between the surface and the actual item. This is one of the things that a window mount does. If you want to display it like that without a window mount, you need to put a spacer around the edge of the rebate.

Generally when you are handling things, always make sure they have a support. This is what you don’t do. This is quite a sound piece of paper, but you always move things on a support because in that way you are not handling them directly. If they are vulnerable, if they are brittle or if they are liable to crease, you actually have something there supporting them and keeping them really nice and solid.

There are some really simple things that you can do. Be aware of your environment. Try to buffer things and try to make sure when you are storing things they are protected from rapid changes in relative humidity, and high and low temperatures. Layers of storage are really important. If you are displaying watercolours, think about where you display them. Don’t put them opposite windows. Try not to hang anything on an outside wall where you may get temperature changes and relative humidity changes. Think about perhaps not having watercolours on permanent display and giving them a rest every now and again and letting them be out of the light for a while. Avoid direct sunlight; avoid UV. A lot of fluorescent tubes will emit UV so try to avoid that.

Equally for paintings, it’s not as crucial in terms of the fading, some pigments can fade and some glazes will fade so again the same principles apply. Handle with care; always provide support. Try to understand what you are dealing with and what the nature of these things are - they may look very robust; they aren’t always. Even something like this on a board - the Museum is about to have an exhibition of bark paintings. One of the things that we had to really look at with the bark paintings is that the bark - it’s similar to a painting on a board - can flex and change with relative humidity changes and it can split. So you can end up with barks - I have seen this with panel paintings as well – that are just split completely because of that change. Although it seems like a really solid material, a lot of these materials can still be quite vulnerable.

It’s about thinking ahead; it’s about housekeeping. The other thing is if you do have a problem with a watercolour or a painting, don’t attempt to treat it yourself unless you really are experienced, because there can be problems with those sorts of approaches if you don’t understand what you are dealing with. It is better to consult a conservator and see what might be done and get some advice so that they can give you a solid way forward to care for your items. Are there any questions?

QUESTION: You mentioned the Japanese paper for the watercolours and the backing for the paintings, where can you buy these supplies?

VICKI HUMPHREY: There are a number of suppliers of archival materials. I am trying to think of the names of them right now. Archival Survival is one of them. If you Google ‘conservation and preservation suppliers Australia’, you will find there are a number of companies that supply these things. Some of them specialise in one area; some of them specialise in other areas. You will have one that will perhaps supply matt board, others that will supply this sort of foam board with paper on either side that is an archival quality. You have to go searching but there are a number of companies. Some of the things that we use we have to import, but that’s very rare these days, there is a good supply of materials in Australia. If anyone would like a list, we can put a list of suppliers on our conservation pages so that people can find them. The AICCM, which is the Australian Institute for Conservation of Cultural Materials, does have a list of suppliers on their website as well. http://www.aiccm.org.au/

QUESTION: Hi Vicki, I want to say thanks for the wonderful talk so far. I have a question for you. I have an Aboriginal bark painting at home. It’s not framed as I don’t want to take away from the aesthetic of the bark. Will it damage the painting to have it mounted without glass?

VICKI HUMPHREY: I think it’s really good that you don’t have it framed. There have been a lot of framing techniques for bark paintings over a period of time and they used to be attached to canvas. There was a period where some quite heavy – heavy in terms of the size of them - moulded mounts were made for them to support them. The way we actually approach mounting, framing and displaying bark paintings these days is to provide a very light support for them that allows the bark to move in responses to relative humidity and temperature. We don’t glaze them.

The other thing with something like a bark painting or anything that has fairly friable media, you have to be careful of your glazing material because you don’t want to have a very chalky ochre attracted to static that gets built up on Perspex. You can glaze with glass or Perspex but you have to be careful which one you are using and the distance you have, particularly if it’s Perspex, away from a friable media.

In saying that we allow the bark to respond to relative humidity and temperature, we do that in the Museum because we do have a reasonably good control over the environment here because there is significant investment in air conditioning and relative humidity control. In our storage areas we actually store the barks flat in deep plan chest drawers and we have boards on which we can pick them up and carry them around. That again is a form of buffering from the environment. You do have to be very careful to make sure that the environment you are displaying it in doesn’t have massive, rapid fluctuations, because that is when you will start to get the splitting. That would be the same with any board and certainly with canvases as well you would have a problem.

QUESTION: Hi Vicki, I have a question. At home I have an acrylic on canvas that is stretched and above a fireplace. Will the fumes and heat from the fire damage it? It was recommended not to frame it as it would be too heavy. Is there anything I can do to look after it, other than move it?

VICKI HUMPHREY: I would move it. If your fireplace is one that you use, I would move it away from there because what you will get there is - the fumes can affect and if it’s open fire. Is it an open fire?

QUESTION: Yes.

VICKI HUMPHREY: You could get the soot, and soot can be quite difficult to remove from the surface of paintings. It takes a lot of work after say a fire to actually remove soot, because it’s oily and it has particles. It’s basically black pigment with oil and it sticks – it is very difficult to remove. The main thing is that you will have heat. So you will have periods of the year where you haven’t got high heat and then you will have a very dry environment above the fireplace and it will be quite hot. I wouldn’t hang anything there. I wouldn’t hang a watercolour there. I think you really need to put it somewhere else where it has much less chance of that extreme change over a period of time. Is it a dot painting or is it just an acrylic?

QUESTION: It’s a dot painting.

VICKI HUMPHREY: One thing that can happen with the dot paintings is that the dots are known to fall off at times. You have to be careful of that. They are little individually placed dots and they are usually on top of another pigment, so they can fall off. I would move it.

One thing I didn’t say, and I will say, is that for any painting or anything that you are hanging, hang it from two points so that, if one fails, it still has something to hang by. If it’s only on one, say it’s a watercolour with glass and it falls and the glass breaks, I have seen a number of watercolours that then get little nicks in the surface. If that falls, it can break the stretcher or strainer; it can cause the canvas to get loose and paint can come off. So always hang with more than one point. If it has a heavy frame or anything like that, think about how many points you are going to hang it from and also what type of wall you are going to hang it on.

QUESTION: (Inaudible).

VICKI HUMPHREY: Are they stretched or unstretched?

QUESTION: (inaudible).

VICKI HUMPHREY: I would treat them the same way. With paintings, all artists use different techniques and use different things. Paintings aren’t just paint; sometimes they are a collage; sometimes you get things stuck to them. Artists are very idiosyncratic in what they put on things - that is Aboriginal artists and non-Indigenous artists. You can have quite complex things. You don’t always get all the ground layers; you don’t always get the proper preparation. My advice would be to treat them all with exactly the same levels of care.

A couple of things that I thought of when you were talking because I know we get a number of paintings at the Museum that come unstretched and are transported rolled. It is really important to note that, if you are rolling paintings, they should be rolled on the outside of a roller and not put into a tube for posting. The same with watercolours - on the outside. You can do a lot of damage trying to get something out of a roller or out of a tube. If it’s on the outside of a roller, you can put layers of protection around it as well. Also that way you won’t get the same sort of distortion. This is a nice little example here that has just been folded over like this. It was given to me by one of my staff the other day as an example. And that distortion is what we have because that’s been folded over. We can’t just flatten that. We have to ease that down over a period of time because we don’t want to split the paint.

If you are rolling a canvas, roll it with the paint side out. There is a reason for that because, if you roll it with the paint side in and the paint cracks and you get compression, when you flatten it you will have a gully in the paint. If you roll it with the paint side out and the paint splits, when it comes back together it will not have that gully. It will still be split but it won’t be immediately obvious. Better not to roll them, but if you have to. Yes, I would treat them with the same care. Try not to put things directly on the surface if you can or definitely something that is not going to stick.

QUESTION: (inaudible).

VICKI HUMPHREY: You can use silica gel and those little silica gel sachets - you would probably need quite a lot of them - but I would tend to try to box them and maybe put them in a couple of boxes with some layers of archival boxing or something like that. That’s one of the problems when you have really large items. Where are you going to store them?

QUESTION: (inaudible).

VICKI HUMPHREY: With temporary storage - I would say get some advice on how to wrap them. That’s another thing: if you are going to put bubble wrap near a painting, never put the bubbles in, put the bubbles on the outside, because the bubbles can leave little bubble mark in the painting, which is not quite what the artist intended. Try to get some archival materials. In fact, if you have a fairly smooth surface, it doesn’t hurt to use archival mount board because that’s quite stable chemically and you could put that on the outside. Don’t wrap them too tight. If they are in a storage unit, put it on blocks. I would put something archival against them on either side, then maybe bubble wrap and then on blocks. Or the other thing you can use is Tyvek, which is a polyester material. You have to put it the right way because it lets moisture out. People wear Tyveksuits in various industries. Tyvek suits let moisture out but they don’t let moisture in. So if that Tyvek material is the right way out, won’t let moisture go in if there is a flood or anything, but it will allow any moisture inside to come out. That’s better than bubble wrap in that sense.

Thank you very much.

Date published: 19 December 2013