The results of conservation research are meaningful to the extent that they can be applied in a practical way. Conservation spoke with three conservators at diverse institutions who have devoted a good deal of time and thought to the application of preventive conservation to objects, collections, buildings, and landscapes.

Sarah Staniforth is the head conservator of the National Trust in England. Formerly a member of the Scientific Department at the National Gallery in London, she joined the National Trust in 1985 as advisor on Paintings Conservation and Environmental Control. She is vice president of the International Institute for the Conservation of Historic and Artistic Works (IIC) and is chair of the United Kingdom Institute for Conservation of Historic and Artistic Works Professional Accreditation of Conservator Restorers Committee.

Richard Kerschner is the director of Preservation and Conservation at the Shelburne Museum in Vermont, where he established the conservation department in 1983. He guided the establishment of the Vermont Museum and Gallery Alliance's Collection Care Program and teaches preventive conservation workshops for the American Association for State and Local History. He is a fellow of the IIC and serves as the treasurer of the American Institute for Conservation.

Jonathan Ashley-Smith is senior research fellow in Conservation Studies at the Victoria and Albert Museum (V&A) in London and a visiting professor at the Conservation Department of the Royal College of Art. Between 1977 and 2002 he was head of the Conservation Department at the V&A. His book Risk Assessment for Object Conservation was published in 1999. In January 2003 he was elected secretary general of the IIC.

They spoke with James Druzik, a senior project specialist in the Science department of the GCI, and Jeffrey Levin, editor of Conservation, The GCI Newsletter.

Jeffrey Levin: The vast number and diversity of things that we wish to preserve present a considerable preventive conservation challenge. Is preserving preventively the full gamut of objects and collections, to structures and landscapes, even feasible?

Sarah Staniforth: The fact that so much heritage has survived until now is evidence of that. The actions taken under the banner of late-20th-century scientific preventive conservation are reworkings of traditional good housekeeping. And I don't mean just good housekeeping of collections but of building maintenance as well. If you look back to William Morris writing in the 19th century, he espoused ''little and often,'' which is what preventive conservation is in the context of building conservation.

Richard Kerschner: I came into preventive conservation about 20 years ago when I became the only conservator at the Shelburne, which is essentially a collection of small museums—we have 40 buildings on 40 acres. Being trained as a treatment conservator, I first built a lab and started treating artifacts. I very quickly realized that working alone I would be lucky to treat 40 artifacts a year. There are approximately 186,000 artifacts in the collection, and I decided that I could not make any progress preserving the collection without preventive conservation. It's just the most efficient way to make sure artifacts last into the future. We now have two conservators—one to do treatment and one to focus essentially on preventive conservation.

Staniforth: Richard, I had exactly the same experience when I was hired by the National Trust to do paintings conservation. I moved very rapidly into doing preventive conservation. There was no point in putting conserved paintings back into damp houses.

Jonathan Ashley-Smith: The reason that preventive conservation will not disappear under any circumstances is because it's actually so easy to do major good just by putting things in a dry place. It doesn't really require a huge amount to make objects last a great deal longer.

James Druzik: What research opportunities will drive preventive conservation beyond the intuition and commonsense housekeeping of the 19th century? Jonathan, I once saw a graphic you prepared that showed preventive conservation at a point where you couldn't justify too many more dollars in at least air pollution research. How true is that for all preventive conservation research?

Ashley-Smith: You can reach a point where you can choose not to put more money into research because you're getting such a small return for it. But museums and organizations are collecting all sorts of new materials, and new technologies in the world outside museums generate new materials. There's always going to be room for trying to understand the way new materials degrade or react with their environment. The general trend lately has been trying to know a lot more about deterioration mechanisms, degradation, and so on. For instance, major European research on paper and leather still hasn't answered all the questions sufficiently to get damage functions or rates of deterioration that help you with usefully predictable outcomes.

Kerschner: I favor research that is pointed toward practical use. Recent U.S. research on safe humidity levels for artifacts has been very important for Shelburne. Under the old guideline of 50percent RH plus or minus 2 percent, we just threw up our arms and said, ''We can't do that.'' The research now indicates that the main damage to artifacts occurs below 25 percent RH and above 75 percent RH. This information opens up a whole range of mitigation actions for museums.

Staniforth: The management of all this is really important. It's all very well having the results of research, but if they're not applied wisely, then you may as well not do the research.

Levin: Can preventive conservation truly be effective in an institution without it being the designated responsibility of a particular individual?

Staniforth: I wouldn't limit it to a particular individual. Having just one expert is not necessarily the most effective way of dealing with this. If you've got a whole department of conservators, then it's helpful for every conservator to understand that preventive conservation is one of their common responsibilities.

Richard Kerschner

Kerschner: I'll extend that to the whole museum staff. Our curators, exhibit designer, protection services personnel, buildings and grounds crews, and collections management staff are all integrally involved in preventive conservation. But without someone like the conservator to champion preventive conservation, integration of preventive conservation actions would not be nearly as effective.

Staniforth: That's nicely put, Richard. The advocacy and champion role of an individual is helpful, along with making it a common responsibility of the whole museum staff.

Druzik: Isn't it the conservator's role to ensure the accuracy and appropriate application of this information that is now in the hands of other staff members?

Kerschner: Certainly. I've also found that it's important to take the right approach to do this, and to work with other staff members to establish credibility. If conservators are too precious or indignant, their advice will be ignored. It is important to compromise when necessary, keeping the big picture in focus. If you get along with and respect the opinions of other staff members, they are more likely to value your advice.

Staniforth: I couldn't agree more. It's team working, isn't it?

Kerschner: It's all teamwork.

Ashley-Smith: In the case of the V&A, it's more a matter of expertise being available and also, possibly, one or two people with good judgment being able to say this is—or is not—a battle we can afford to lose. People want us to help them store collections under the right conditions. I think those are the two sides, the judgment and there being real expertise somewhere in your building—someone who actually knows what you're talking about rather than providing quick answers out of a book.

Levin: And has that process worked fairly fluidly in your own institution?

Ashley-Smith: I would say so. None of our storage areas are high tech, but they're all clean, well organized, and the objects are not deteriorating rapidly. And we have things like the integrated pest management system, which involves everybody from curators to cleaning staff.

Levin: Would you say that the ability to make the concept of preventive conservation a pervasive one is as key to its success as having the knowledge itself?

Ashley-Smith: Training is essential. Through the conservation department, we've put a lot of effort into getting general concepts over to the people who want to know the answers—curators, collections managers, and so on. Every few years, we have a big push trying to get the latest concepts of conservation over to people.

Druzik: There's a lot of energy and resources that can go into preserving collections and buildings, but when it is not maintained, it's a wasted effort. How do you sustain it?

Ashley-Smith: One way is to do what's been done at the V&A for a long time now. Any project that involves the collection automatically has a conservator on the project team. This has two purposes. One is to make sure that if there's a demand for interventive conservation, it is recognized early on, and it gets into the program. The other is to make sure that before individual objects go into storage or display, someone looks at them from the point of view of, ''no, don't put them there because that's too light ''or ''don't put them there because people are going to touch them,'' and so on.

Kerschner: At a smaller museum like Shelburne, we do the same thing on a more informal basis. The fact that we have a conservator at the senior staff level—and that I can freely communicate with all the other staff members directly involved in a project—is extremely important in promoting preventive conservation actions.

Staniforth: Can I just go back to a word that Jonathan used, which was ''project”? One of the things that makes me uneasy is the move away from operational budgeting that pays the salaries of maintenance staff and encourages the ''little and often.'' The budgets for staff salaries are being shifted into big projects as organizations move into this project culture. That is what's happening in the U.K. We do not have the operational budgets to pay for the levels of preventive conservation that collections need, and therefore we fund more and more preventive conservation through projects.

Ashley-Smith: I agree. In terms of sustainability of conservation, it's best having people around who know the collections and can be there on a day-to-day basis to do that ''little and often'' maintenance. Departments such as the one at V&A have people around to make sure things are kept under control. However, in a lot of museums there is a decrease in permanent staff and a decrease in specialized staff, with staffing growing much more out of a contract, project-based environment. This is a real long-term danger.

Kerschner: We've been practicing project-driven preventive conservation for the last 15 years. Much of our preventive conservation money comes as grants from the Institute for Museum and Library Services and the National Endowment for the Humanities. We've implemented projects for fire, security, lighting, and environmental improvements. Without that money, which is significant, we would be nowhere near where we are regarding preventive conservation actions.

Ashley-Smith: In terms of step-by-step improvement, the project is a good way of doing it. But you're not necessarily left with the money to maintain what you've just achieved.

Kerschner: I believe that one of the reasons that we received one large environmental improvement grant is that we recognized that we would have to permanently add a person to the staff to maintain the equipment being installed under the grant, and stated our willingness to do so in the grant application.

Staniforth: It's difficult in the United Kingdom to get endowments for the ongoing maintenance and staff costs. Granting bodies, on the whole, won't give money for endowments. You have to rely on gifts.

Levin: What I'm hearing here is that at a time when conservation is moving toward preventive conservation—which of course is long term at its foundation—the surrounding culture embraces a short-term perspective.

Staniforth: It's a real concern. Our lives are driven by the short term, aren't they? If you compare our situation with that of the environmental movement, we face the same challenges that they do, in that no one in government cares what happens in 25 years' time. They're worried about getting elected in the next term. That's probably as true in the States as it is in Europe.

Kerschner: This influences the way we design our projects. We have to look at sustainability very closely, realizing that after we've installed or upgraded equipment, we will have to maintain it on our own budget. We strive to install practical, uncomplicated environmental control, security, or fire protection systems. This may mean adapting commercial equipment to meet our needs rather than purchasing specialized industrial equipment. Such systems are less expensive and can be easily serviced by local contractors.

Ashley-Smith: When we talk about long-term things under the banner of preventive conservation, getting something mechanical maintained probably isn't too difficult. But what about lower-level preventive conservation needs? For example, we have a large library collection. You can keep books from falling apart or tears getting worse with just a low level of maintenance or interventive conservation, which prevents damage. If that sort of thing is project driven, museum administration, when looking at its priorities, will say, ''Yes, you can have a conservator for this project.''It won't say, '' Yes, you can have a conservator sitting here stopping books from falling apart.''

Staniforth: In talking about the short-term view in the context of economic sustainability, if you take something as simple as applying UV filters to windows, you're probably not going to see the benefit of them within five years. You're looking at a longer-term benefit. And the accountants aren't very interested in benefits that might be seen in 10 or 25 years.

Druzik: Those UV filters may have to be replaced several times before the absence of those filters would show up. That means you have replacement procedures with no detectable benefits to the museum director. It takes faith on the part of the director to accept that this needs to be done. That's the kind of sustainability that one fears is threatened.

Staniforth: It's the sort of cost-benefit research that's interesting to do. With paintings collections, you can look at the rate at which the varnish discolors and therefore needs to be removed and relate that to the frequency with which you need to replace the UV filters, and you start to get a cost-benefit analysis.

Kerschner: It is frustrating. If we do our preventive conservation job well, we prevent the damage to artifacts that ultimately proves our advice was correct. Of course, one can cite past damage to promote preventive conservation actions. Before conservation was established at Shelburne, some dolls had been displayed under fluorescent lights for over 40 years. The staff did the best they could years ago when they set up those cases, but improper lighting damaged the doll costumes. I'm able to point to some of these dolls that were too close to lights and say, ''This is what happens, and that's why we have to protect them from excessive light in the future."

Druzik: Is the conservator in the trenches, who is just trying to keep the environmental conditions stable as he or she sees them, even considering assessing risks more than just stopping imminent catastrophes?

Ashley-Smith: During my time at the V&A conservation department, I did manage to move the on-the-ground conservators more toward risk assessment and therefore to become less risk averse. Given that some conservators can be a bit dogmatic, if you can get them to use judgment and consider risk assessment, then that's a good thing. If you don't take the most extreme view of the precautionary principle, then risk assessment including cost-benefit analysis—using the precautionary principle as some sort of guide—brings you to a sensibly risk-averse way of dealing with collections. Then you actually end up with a slightly more old-fashioned, but sensible, conservative view about how things ought to be dealt with.

Druzik: It's really a delicate line to walk, isn't it, because the 50 percent plus or minus 2 percent RH is a quintessential risk-aversion position. The idea of assessing risks and allowing those humidity conditions to stray a bit can be terrifying when you consider the potential damage if the sensors are not giving you the information you need to assess that risk carefully.

Staniforth: There's nothing like a disaster to put those things in perspective. One of the most influential events in my professional life was dealing with a house that burned down. It made me realize where the gains are to be made by good preventive conservation. Of those nine agents of deterioration, dealing with fire, prevention of theft and vandalism, and making sure you've got a sound building are going to get you the greatest cost benefit. I think that helps you to understand the whole concept of risk and to avoid being risk averse.

Druzik: When you put it that way, Sarah, it seems to boil down to just a lot of common sense. Maybe there's nothing that really distinguishes common sense and preventive conservation.

Staniforth: The more I do this job, the more I come to that conclusion.

Kerschner: Same here. Common sense is the basis for preventive conservation.

Druzik: So when you finish reading a new piece of research, do you sit back in your chair and say, ''That's what I thought in the first place. I knew that.''

Ashley-Smith: Well, knowing how much faster leather will degrade if there's more sulfur dioxide in the air—those sort of figures are not intuitive. The results follow your intuition, but actual numbers can be useful, and that's what the research is all about—providing the numbers.

Druzik: In the United States, as well as in some other countries, there is a concept among some manufacturing and engineering firms to document procedures and testing to a rather painful degree of precision, in order to guarantee that the product retains fidelity and quality over the long term. In conservation, we're making a lot of assumptions about the products that we're using. How does one maintain, over several careers, the same qualitative approaches to specifying materials that are used that attain desired results?

Ashley-Smith: What you've just described is a sort of quality control, but to a standard procedure. It does happen in the museums with which I am familiar, but not in a totally formal way. For example, anytime anyone wants to put new UV film on any windows in the V&A, the product is definitely tested.

Kerschner: At our museum, I am the quality control for preventive conservation actions. If we're going to install a filter, I do the research and find out which filter is best to use. If there were not a well-trained conservator here who knew where to find the information, I'm not sure how well the job would be done.

Druzik: So in a certain sense, in a small institution, it cannot be sustainable.

Kerschner: I question whether staff members with primary responsibilities other than conservation will consistently follow preventive conservation standard procedures year after year. What makes preventive conservation really sustainable at smaller institutions is having a person with the appropriate knowledge directly responsible for it. This may not have to be a conservator, but I think it helps if it is.

Ashley-Smith: There is a need for a greater agreement about protocols in all aspects of museum life, but the people whom I speak to are all fairly much against the introduction of universal standards, which is what this sounds like. I think people should have some local judgment and local ability to alter things. If your standards become too rigid and your process automatically enforces those standards, that can be a bad thing in the long term.

Levin: This whole issue of standards versus guidelines is something that has rumbled around in conservation for quite a while. Are preventive conservation standards the most appropriate approach, or are guidelines more realistic? That seems to be what you're saying, Jonathan.

Ashley-Smith: I suspect that in the long term no one will be able to distinguish between guidelines and standards, but standards can become easy to use in a dogmatic fashion. In the U.K., with our lottery funding, you must abide by these standards or you won't get the money, even if it turns out that particular standards are not applicable in your local situation. So you can use standards in a bad way.

Kerschner: In my situation, guidelines are exactly what we need. They have to be reasonable and they have to be attainable. I may not eliminate the last bit of UV because I haven't selected exactly the right filter, but what I'm looking at is improving conditions, not necessarily getting to what is the perfect condition under this standard. This ''improving conditions'' approach has served us very well.

Staniforth: Well, the National Trust manages about 160 registered museums, with 240 houses open to the public and something like 30,000 buildings altogether. We entirely use guidelines, and it's very much related to what's achievable and pragmatic. We definitely go for making things better rather than for perfection.

Druzik: Do you specify the limits that they can drift within guidelines?

Staniforth: No. To take an example, the guideline for relative humidity control would be to avoid the extremes above 65 percent and below 50 percent. But we would not say to an engineer, ''We want the relative humidity to stay between those two levels.'' The problem with historic buildings is if you give an engineer a tight specification, they will take it literally, and they will put in equipment that will never allow the RH to go above 65 percent or under 50 percent. That introduces machinery into a historic building that you just don't want there.

Kerschner: In Vermont, we're happy if we can keep relative humidity below 65 and above 35. We cannot adhere to a standard that's international. It depends on where you are, what your buildings are, whether they are heated, and so many other different factors.

Druzik: It's certainly true that the use of guidelines is profoundly affected by geography. In Southern California you can spend millions on HVAC equipment and not affect a Santa Ana wind condition, when the outside humidity dips to 2 percent. There's no machine in the world that can do that outside of a sprinkler system—which for obvious reasons is not very effective for preventive conservation.

Staniforth: We're inching into talking about the wider environment and global warming. We're having interesting changes in the climate in the UK and, particularly, more extreme weather events, which we're trying to adapt to. We're getting warmer, wetter winters with a lot of heavy downpours, which are affecting buildings. When you put in an environmental control system that copes with more extreme weather, you actually use more energy, which then increases the global warming that is causing the more extreme weather.

Kerschner: It's important that any system one does install works with nature instead of against it. We could heat more of our buildings and install humidifiers to increase humidity during the very cold winters, but that's working against nature globally as well as locally. Instead, we just keep the buildings cold so that the RH stays at a safe level. This certainly affects how people can visit, or even if the buildings can be open in the winter. But that's the type of decision that has to be made.

Staniforth: Actually that's an interesting way of engaging the public, because you can use that as a learning opportunity for visitors. Which brings us right back to the way in which all of these preventive conservation issues relate to our constituency and the way in which the philosophy of preventive conservation leads to sustainability in a much broader sense. Our parents and our grandparents were much more economical with the resources that they used. There are huge lessons to be learned.

When I taught at the GCI preventive conservation course, I talked about the way in which we're controlling RH in the National Trust Historic Houses. We use low levels of heating to bring the humidity down to below the mold threshold, which consumes considerably less energy than comfort heating for people. One or two course participants said that the collections that we look after are so important that the amount of energy we use doesn't matter. I couldn't disagree more. It's our responsibility as museum professionals to look at that wider environment and think about our social responsibilities, as well as our responsibilities to the collections.

Levin: So when you talk about sustainability, you're not only talking about the cultural institution and its collections, but also about the wider environment in which that institution exists.

Staniforth: Absolutely. We're in the heritage business, and the whole point of what we do is to pass on our cultural heritage to future generations. What's the point if they're actually going to be much more concerned about their own survival? We have to have an eye towards the wider environment and what's going to happen in a hundred years' time for the sake of our children.

Druzik: I don't think you have many people saying now that we've got to put all these systems in because our collections are so important. Instead, they're looking for ways to manage money wisely and to use technologies that are sustainable.

Ashley-Smith: I think the reason that people's minds change is purely the short-term cost benefit of relaxed environmental parameters. It has the benefit possibly of using less energy and therefore not using up resources or destroying the atmosphere. You can use the short-term cost-benefit argument to get what you want, which will have the side effect of being more sustainable.

Kerschner: One of the things that we're looking at is using household air-conditioning systems—not to decrease summer RH levels to 50 percent or even 55 percent, but to get down to around 60 percent RH. That RH level is safe for the artifacts in our historic houses, and it is a significant improvement over present conditions. I agree with Jonathan that it would be nice to be able to say that we're concerned about global warming, but our actions are largely driven by the bottom line. If we can save costs and energy, then that's what makes us do it. And if our actions are also good for the environment—great. I wish it were the other way around, but I don't think it is.

Druzik: Another question I have is the potential of expert systems for preventive conservation. This is an area where Rob Waller and Stefan Michalski in Canada have been engaged in research [see Effective Preservation: From Reaction to Prediction]. I'd be interested in what the three of you have to say about the possibility of developing these sorts of systems and their potential for providing a structured way of ensuring quality control.

Ashley-Smith: I wouldn't advocate any system that stops people doing the thinking themselves, possibly because I like to think these things out myself. However, there are a lot of curators or conservators or people running small institutions who want to be told what to do. Expert systems can tell you what to do in a structured way that takes into account other people's judgments, and that's good in that respect. I personally wouldn't like it if you couldn't see how it works and understand who is saying what and why they're giving you that information. From a brief conversation with Stefan, it sounds as if you can get deeper into the system if you want to. As long as people who want to think for themselves can use it with more judgment, I think it will be good.

Staniforth: I can see how it might be used in a museum with a largely professional staff. But in a very diverse organization with an awful lot of staff who are trained to do what they do, I think it would be a real challenge to put into practice those sort of systems.

Druzik: I think what you're saying is you wouldn't want to get into a 747 and fly it with an autopilot and have no idea how the thing operates.

Staniforth: That's what Jonathan was sort of saying. If you've got the ability to understand what it's doing, then it can be a useful tool. In the hands of our managers of historic buildings, I'd probably worry.

Kerschner: I get the best buy-in for preventive conservation actions if everyone on the project team can understand the action and the reason for it. I have found Stefan's preventive conservation work to be very practical and helpful for small museums, so I will seriously consider any system he develops.

Staniforth: I just wanted to say a little bit about the role of the conservator in all of this. I think that preventive is a very unfortunate word. At the National Trust we've got some preventive conservation advisors, and some of my colleagues have asked me, ''What do they do that prevents conservation?'' I like to feel more positive about what we do and that our role, in fact, is to enable sustainable access.

Kerschner: I like the concept of ''sustainable access.'' What I sometimes struggle with is the conflict inherent in improving access to collections and, at the same time, addressing the need to preserve the collection. I believe in more access, but isn't there a point at which that becomes counterproductive?

Staniforth: You have to have a tool kit that looks at that balance between conservation and access. One of the things that we've been developing is a working tool which deals not just with light hours and wear and tear but also with the financial costs of giving more access—and that's in staff time. If you've got more people coming through, you've got more cleaning to do, because they create more dust.

Kerschner: In the United States, the National Endowment for the Humanities has funded many conservation projects out of their Division of Preservation and Access. They do not want to fund the preservation of artifacts that are then hidden in storage. They want collections available to people, and they use their grants to fund preservation actions that encourage responsible access.

Ashley-Smith: When you use the words sustainable access, you're also talking about people who don't yet exist. You have to deny some access now for the sake of future generations.

Druzik: This very quickly gets you into establishing what is acceptable damage over a specified period of time. The instant that that is conceded, you automatically cut out some people.

Ashley-Smith: With lighting, for instance, you have to accept damage. All light-sensitive objects are being damaged when displayed under light. That's an area where the notion of acceptable damage has become accepted.

Levin: We live in an age where access is critical for sustaining public awareness of the importance of collections and structures and landscapes, as well as for justifying their preservation. And so the challenge that preventive conservation has to address is, as you put it, sustainable access—sustaining all these things that we've come to treasure as demands increase for them to be accessible to the public.

Staniforth: Yes, absolutely. The reason we do this is for people. We're not doing it for the objects.