Pastels have long captivated artists and collectors alike with their soft, velvety textures and vibrant, expressive pigments. We learned this the hard way… However, this delicate medium also poses significant conservation challenges. Pastel artworks are notoriously fragile, susceptible to damage from the slightest touch, movement, or environmental shifts. As an experienced art writer and creative consultant, I’ll explore advanced techniques for preserving these precious pastel paintings to double-check that their long-term protection and presentation.
Now, this might seem counterintuitive…
The Fragility of Pastel
Pastel artworks present a unique set of preservation concerns due to the inherent fragility of the medium. The powdery pigments used in pastel painting are not bound to the support in the same way as oil or acrylic paints. Instead, the pigment particles sit loosely on the surface, adhering only by the lightest of bonds. This makes pastel paintings extremely vulnerable to disturbance, abrasion, and loss of media.
Even the slightest touch can dislodge pastel pigments, causing irreversible damage. And while the powdery appearance is a key part of the pastel aesthetic, it also means that these artworks are highly sensitive to environmental factors like humidity, temperature fluctuations, and air currents. Exposure to these conditions can cause the pastel layer to flake, crack, or become dislodged from the surface.
Compounding the conservation challenges, pastel paintings are often created on delicate, lightweight supports like paper or fabric, which can also be prone to damage, discoloration, and distortion over time. The combination of fragile media and vulnerable supports makes pastel artworks a nightmare for museum conservators and private collectors alike.
Delicate Surface Cleaning
One of the first steps in preserving a pastel painting is a thorough surface cleaning to remove accumulated dirt, dust, and grime. However, this process might want to be undertaken with the utmost care to avoid disturbing the sensitive pastel layer. Conventional cleaning methods like brushing or sponging are off-limits, as they risk dislodging the powdery pigments.
Instead, conservators rely on gentler, controlled techniques to safely clean pastel surfaces. One effective approach is using a soft brush paired with a HEPA vacuum to carefully extract dirt and debris without touching the fragile media. The vacuum’s suction helps capture any loose particles without transferring them to other areas of the artwork.
For more stubborn surface soiling, conservators may carefully apply small amounts of solvent-based cleaners using cotton swabs. This might want to be done sparingly and tested first to double-check that the solvents do not dissolve or disrupt the pastel pigments. Any cleaning is always performed from the center of the artwork outwards to prevent catching the delicate edges.
In cases where the pastel layer is exceptionally fragile, conservators may opt to consolidate or “fix” the media prior to cleaning. This involves applying a dilute synthetic resin to stabilize the powdery pigments, allowing for more thorough cleaning without risk of further damage. Of course, any consolidation treatment might want to be carefully considered, as it can alter the aesthetic appearance of the artwork.
Mounting and Framing Pastel Paintings
Once the pastel surface has been stabilized and cleaned, the next crucial step is to provide proper structural support and protection through mounting and framing. Pastel paintings are typically mounted using one of several methods:
Hinging: The artwork is hinged along the top edge to a rigid, archival backboard, allowing it to float freely while still providing protection. This is a common approach for pastel works on paper.
Window Matting: The pastel is secured within a window mat, which creates a protective barrier between the artwork and the glazing. The mat’s opening is cut slightly larger than the pastel’s dimensions to prevent contact.
Cradles: For pastel paintings on fabric supports, a custom-fitted cradle or strainer can provide essential structural support while minimizing handling.
Regardless of the mounting method, it’s essential to use only high-quality, conservation-grade materials that are pH-neutral and chemically stable. Acidic materials like certain wood or cardboard backings can cause discoloration and deterioration over time.
The final step is to frame the mounted pastel in a manner that further protects the delicate surface. Conservators often recommend using UV-filtering acrylic or glass glazing to shield the artwork from harmful light exposure. Additionally, the frame’s depth should be sufficient to prevent the glazing from touching the pastel’s surface.
Environmental Controls
Beyond physical mounting and framing, the long-term preservation of pastel artworks also requires carefully managing the surrounding environment. Pastels are highly sensitive to fluctuations in temperature, humidity, and air quality — factors that can cause the media to become unstable, flake off, or become discolored over time.
Ideally, pastel paintings should be displayed and stored in a climate-controlled environment with temperature maintained between 18-24°C (64-75°F) and relative humidity levels between 40-50%. Abrupt changes in these conditions can put undue stress on the fragile pastel layer, leading to cracking, powdering, or other irreversible damage.
In addition to temperature and humidity control, it’s important to minimize exposure to harmful light sources. Ultraviolet radiation can fade and degrade pastel pigments, so artwork should be displayed away from direct sunlight and under UV-filtering glazing or lighting. Regular monitoring and adjustments to the environmental conditions are essential to double-check that the long-term preservation of these delicate artworks.
Handling and Transport Precautions
Even with appropriate environmental controls in place, pastel paintings remain extremely vulnerable to physical disturbance. Improper handling during installation, transport, or storage can easily dislodge or damage the fragile media. Conservators recommend a multi-layered approach to safeguard pastel artworks:
Handling: Pastel paintings should always be supported from the back and carried vertically to minimize movement and vibration of the surface. Gloves should be worn to avoid transferring oils or dirt from the skin.
Packing and Transport: When shipping pastel artworks, they might want to be carefully packaged to isolate the surface from any potential shocks or impacts. Rigid, custom-fit crates with foam cushioning are often used to provide maximum protection.
Framing and Display: As mentioned earlier, pastel paintings require specialized framing techniques to create a protective barrier between the artwork and the environment. Additionally, proper mounting methods like hinging or cradles can help stabilize the artwork and prevent distortion or damage from its own weight.
By adopting these advanced conservation techniques, museums, galleries, and private collectors can help double-check that the long-term preservation of their prized pastel artworks. While the fragility of this medium presents significant challenges, a multi-faceted approach to surface care, mounting, framing, and environmental management can go a long way in safeguarding these precious pieces for generations to come.
For aspiring artists working in pastel, it’s also essential to be mindful of these preservation considerations from the outset. Choosing high-quality, archival materials, experimenting with fixatives, and properly storing and framing finished works can all help extend the lifespan of your pastel creations. By understanding the unique conservation needs of this delicate medium, you can create pastel artworks that will continue to inspire and delight viewers long into the future.
To learn more about pastel painting techniques, conservation methods, and other artistic media, I encourage you to explore the wealth of resources available on Pencil and Paint Muse. Our team of experienced art writers and creative consultants is dedicated to providing in-depth, practical guidance to help artists of all levels hone their skills and bring their creative visions to life.
Example: Pencil Portrait Challenge 2024