Preventive Conservation encompasses all of the activities that enhance preservation of collections without direct intervention with the material fabric of objects. These include environmental factors (relative humidity, light and UV, temperature, and pollutants), integrated pest management, as well as good care and handling practices.
At the RAM, the conservation, exhibition, collections management, and curatorial teams work continuously to ensure that preservation risks to objects are mitigated as much as possible during storage or exhibition.
Have you ever thought that light levels were too low in museum exhibits? Check out this image of a toy furniture piece from the RAM's collection that has sustained light damage through being on long term exhibition. Remnants of the original bright pink can be seen in the area hidden by the couch cushion while it was on display. Aside from discolouration, the silk has suffered extensive structural damage, evident in the brittleness, splitting, and numerous areas of loss. Unfortunately, light damage is cumulative and irreversible.
One of the ways that we mitigate the risk of light damage is to keep light levels low, especially for objects with high sensitivity. Another way that we can mitigate the damage is to rotate the display of artifacts that are light sensitive, to prolong the lifetime of the object and safeguard it for future generations. Finally, UV light is always eliminated from exhibition lighting, since UV is composed of short high energy wavelengths that are very damaging to art and artifacts, and is unnecessary for viewing (in fact, it's not visible at all!).
It's equally important to prevent damage to objects that occur due the presence of pollutants and contaminants in the exhibit or storage environment. In this image of a lead toy soldier, you can see large white crystals erupting from the core and disrupting the paint surface. These crystals are lead acetate and/or lead formate, corrosion products that are produced when lead is in an acidic environment, such as contained inside a wooden drawer or display case. While some woods off-gas more organic acids than others (oak, for example, is one of the most acidic woods), all wood products will off-gas to some degree.
This is harmful not just to lead. Many materials are sensitive to organic acids: silver will tarnish, iron corrode, papers and textiles will deteriorate (invisibly). To prevent these types of damage, we try to avoid the use of wood and acidic paper products in storage, instead using "archival quality" materials that are stable and compatible, like powder coated baked enamel metal shelving and acid-free tissue. For exhibit furniture, we carefully select inert or stable building materials. If wood products must be used, we ensure that an effective vapour barrier seal has been applied to prevent off-gassing. Finally, we apply the same degree of care in the selection of paints, adhesives, and caulks, so that all exhibit construction materials are non-reactive.
We employ many different strategies at the RAM to prevent pest damage to the collections, such as inspection, isolation/quarantining, carbon dioxide (anoxia) fumigation, and freezing. These, combined with regular monitoring and good housekeeping practices, comprise our Integrated Pest Management Program.
One of the greatest threats to the preservation of an artifact or specimen is actually accidental damage through handling. That's why the final piece of the preventive conservation puzzle is a set of comprehensive care and handling practices and policies for our staff, volunteers, and researchers.
An ounce of preventive conservation is well worth a pound of conservation treatment! Treatments are time consuming and the number of conservators on staff is very limited compared to the millions of artifacts in the collections. We know that it would be simply impossible for RAM conservators to individually treat all of the artifacts in the collection, but by working on preventive conservation measures such as those outlined above, we can help safeguard the museum's collections for future generations to enjoy.
Content: Shirley Ellis
Those beads are heavy!
Even though these dresses look strong, when on display the weight of the beads would put a lot of stress onto the sheer fabric. Over time we could see some tearing and damage to the fabric. These two dresses are from the 1920s, a period in time when flappers, short hair, shorter skirts and a boyish-type body were in fashion. Dresses of this time period were less restrictive and designed to move. The weight of the beads would help to make them swing!
When these dresses are on exhibit, it is important to reduce the pull of gravity so displaying them horizontally or on a low angle is best. Some shaping makes it look more body-like.
First a tracing is made of the dress, then this drawing is transferred to the ethafoam where it is carved out. The ethafoam needs to be a bit smaller than the dress itself, to allow for the added thickness of the foam (1") and the polyester batting that will be wrapped around the foam to provide some cushioning.
This gives the heavy beads a soft surface to lie on, providing some support to the beads as they sink into the padding a little bit. Overall, the support, with additional padding, still needs to be smaller than the dress so that there is no stress when the dress goes on or is inside.
The polyester batting is shaped in the bust, tummy and skirt areas by adding or layering extra batting on the support. This helps the viewer to get an idea of how the dress would really hang and move on the body. We are not flat and neither is the support. The padding goes right around the Ethafoam providing a soft surface for the beads, both on the front and the back of the dress. The green dress has a little blousing just above the hip area so a secondary support underneath the dress was made which allows for this blousing fabric to sit in a nest, minimizing creasing and crushing. It is constructed from a rigid plastic material called coroplast, a "safe" plastic (polypropylene copolymer) used in museums, with a layer of polyester batting to provide that soft cushion. The area that corresponds with the dress's blousing was cut away.
In the end, with adequate support, the dresses can be displayed safely for you to enjoy!
Content: Carmen Li
Have you ever wondered how museum garments are displayed; what resides beneath the surface? We all know from our daily experience that one size certainly does NOT fit all, and that's also the case with mannequins and dress forms, so there is always far more than meets the eye when garments are exhibited.
For the contemporary art garments displayed in the feature exhibit Western Threads, we wanted to make hollow-form mannequins. These are custom forms that are moulded to the exact size and shape around a model. Because they're hollow, they have the advantage of appearing almost "invisible" or "floating" when on display.
In this case, we were very fortunate that the dresses were made by local artists, and to their own measurements. With the artists as our models, we got to work! Kraft paper was used for the lightweight silk dress, while heavier duty plaster bandages was chosen for the velvet corset and skirt. The Kraft paper was applied in a herringbone pattern to give more strength to the form. Plaster bandages, on the other hand, were applied in small overlapping strips. Plaster bandages are easy to shape and mould when wet (if a bit messy), but forms into gypsum when mixed with water, setting into a lightweight and resilient structure.
Once the forms were set, they required additional shaping to fit and support the garment. This is a step that's necessary for all mannequins, including (and most especially!) standard sized commercial mannequins.
Historic garments are particularly tricky to fit. We often have to carve, pad out, cut down, or otherwise adjust mannequins substantially in order to provide the proper support for the garment, and to achieve the right look for the garment. The forms are then in a knit jersey, followed by a display fabric for the visible areas.
It takes a lot of time and effort to custom-make these "invisible" hollow-forms, but as you can see, they show off these two beautifully designed and gorgeously constructed garments to perfection.