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Conservation of Modern Pastel Artworks for Artists and Collectors

  • Writer: Andre Rios Art
    Andre Rios Art
  • 1 day ago
  • 7 min read

Pastel artworks possess a unique luminosity and delicacy that make them both captivating and vulnerable. While modern materials like Pastelmat paper and high-quality pastel pencils from Stabilo and Caran d’Ache have greatly improved the stability of pastel drawings, their proper care and conservation remain essential—whether you are the artist or the collector. In this article, we’ll explore up-to-date guidelines for preserving pastel artworks, combining traditional conservation principles with insights tailored to today’s tools and materials.


Preventive care is critical because pastel media (soft pastel, pastel pencils) are inherently fragile. Pastel drawings have “very little binder,” so the pigment particles lie on the surface and can easily smear or dislodge. As the Rijksmuseum notes, pastels are “one of the most fragile artworks” – “the medium is barely attached to the support, each movement is a risk”. Even when using modern archival materials (e.g. Pastelmat paper, which is acid-free and pH-neutral), the image can be disturbed by touch, gravity or environmental changes. The goal of preventive conservation is therefore to minimize exposure to light, dust, moisture, fluctuations and physical stress, and to frame and store pastel works so that the powdery surface never contacts anything.

Pastels are light-sensitive (pigment-dependent), so lighting and climate control are paramount. Use low-intensity, UV-filtered lighting (LED or filtered fluorescence) and avoid direct sunlight. Museums recommend keeping pastel rooms cooler and darker; for collectors at home, hang artworks away from windows and use curtains or UV-filter film. Icon (UK) advises a stable environment of about 16–19 °C and 45–60% relative humidity. In particular, avoid high humidity (above ~60%RH), because moisture can soften paper and even cause severe mold growth on pastel media. Likewise avoid heat sources (radiators, spotlights) and exterior walls prone to condensation. In summary:

  • Maintain stable, moderate climate: Aim for ~18 °C and 45–60% RH; sudden changes and extremes damage paper and pigment.

  • Limit light exposure: Use UV-filter glazing and low light levels (e.g. 50–100 lux) for display. Icon specifically warns to “protect framed … watercolours from daylight” and use UV-filtering glass.

  • Prevent dust and pollution: Keep pastel pieces behind glass or in closed cases; avoid smoky or dusty environments. Use air filters or keep art in sealed frames.


Storage and Handling

When not on display, pastel drawings should be stored flat and supported, not rolled or tightly stacked. The best practice is to keep them in a flat file or archival portfolio box, face up on a rigid backing. Interleave artworks with acid-free tissue or glassine to cushion them. Ordinary plastic sleeves are not recommended for fragile pastels. A few tips:

  • Store pastel works horizontally in conservation-grade boxes or folders. This isolates them from dust and allows safe handling. Acid-free envelopes, folders or board-lined portfolios provide good protection. Use cotton or buffered board supports.

  • Interleave each sheet with acid-free tissue to prevent adjacent images from touching. This also helps absorb any acids.

  • Keep storage areas cool, dry and dark, away from heat or water sources. A closed cabinet or drawer is ideal. Don’t store pastel art in basements or attics (risk of damp or heat).

Handling precautions are crucial. Always touch pastel artwork as little as possible. Wear clean cotton or nitrile gloves, and never rub or press on the painted surface. Instead, lift and move by the edges of the backing or mount. Support the work on a rigid board when carrying it – do not flex it. When examining or photographing a pastel drawing, avoid breezes or fans that could blow loose pigment. In general:

  • Minimal contact: Handle pastel art only at edges, and preferably over a table or with two people for large works.

  • Permanent framing: For works kept out of storage, consider permanent encapsulation: Icon UK even suggests keeping pastel/charcoal works permanently framed in a rebated mount to prevent smudging.

  • Regular inspection: Check stored pastels periodically for dust, pest damage, or signs of flaking. If you see loose pigment, it indicates need for professional attention.


Framing and Mounting

High-quality framing is one of the most effective ways to preserve pastel drawings. Follow museum-level conservation framing practices:

  • Glazing (Cover): Always use UV-filtering glass or acrylic. Glass is generally preferred for pastels, because acrylic can build up static charge and attract pastel dust. (Icon UK explicitly warns that standard acrylic glazing “should never be used to glaze pastels” due to static). If using Plexiglas/Acrylic, choose a non-static or UV-filter type and include mat spacers.

  • Mat/Spacer: Incorporate a spacer or thick window mat so that the glass does not touch the pastel surface. A margin of air space prevents the artwork from sticking to the glazing or abrading. Icon UK’s checklist specifies that “glazing material [be] spaced away from the picture surface”. Anti-static interleaving papers (e.g. acid-free tissue) may also be used under the mat as an extra buffer.

  • Mat boards: Use conservation-grade mats and backboards (100% cotton or buffered wood-pulp core). These protect the drawing from acid migration. Do not use cheap cardboard or foam-core that can yellow and off-gas. The mat window should be slightly larger than the image, and the pastel should be secured only at the top edge with archival paper hinges (no tape on the image!).

  • Frame depth: Choose a deep frame with a wide rebate so that there is room for the mat, glass, and backing. This also allows a sealed environment: Icon notes the frame should accommodate glazing, window mat, under-mount, and backboard in a way that “isolates” the artwork.

  • Sealing: Seal the back of the frame with archival sealing tape to exclude dust and insects. The Icon guideline suggests gummed tape on the frame edges for a “sealed” package.

Key conservation framers’ rules include: no direct contact between pastel and any surface (no tape, adhesive, or glass touching the drawing), and non-reactive materials throughout. CCI (Canada) specifically warns that static or friction from glazing without proper spacers can “cause serious losses” of pastel pigment. In short, frame pastel works to keep them completely stationary and isolated from air pollutants.


Materials and Lightfastness

Choose archival-quality art materials. For example, Clairefontaine Pastelmat paper is marketed as archival (acid-free, pH-neutral) and is designed to hold pastel layers. Always use buffered/museum-grade mats and backing boards. When using pastel pencils (e.g. Stabilo Carbothello, Caran d’Ache), note that these brands generally have high pigment and good lightfastness, but it’s wise to check each color’s rating. Because most pastels have minimal binder, the pigments themselves determine fade-resistance. Verify lightfast ratings (ASTM or manufacturer) before use, and assume sensitive pigments should be kept dimly lit.

Avoid non-archival adhesives or tapes. Do not press any sticky tape onto the artwork – tapes often leave stains or exacerbate acidity. Attach drawings with archival paper hinges (using wheat starch or methyl cellulose paste) only at the edges. Likewise, never use glues, staples, or self-adhesive labels on the image or verso.


Restoration and Repair

If a pastel artwork is damaged (e.g. flaking, tears, stains), consult a professional paper conservator. Do not attempt harsh cleaning or repair at home. (Well-meaning remedies – bread crumbs, scotch tape, household cleaners – will usually do more harm.) However, it is useful to know the typical conservation treatments:

  • Consolidation:  For flaking or powder loss, conservators may apply a very dilute adhesive (“consolidant”) over the pastel surface to re-adhere pigment. Common choices include Klucel® G (hydroxypropyl cellulose) in alcohol or acrylic copolymer resins (e.g. low-concentration BEVA or Plextol). This process is delicate: many adhesives can alter the appearance. In fact, studies have shown most fixative sprays tend to dull pastel colors, except reversible resins like Paraloid B-72 or Aquazol 200 which preserve brightness better. Therefore, any fixation should be done sparingly and only after tests.

  • Fixatives:  Commercial pastel fixative sprays are not usually needed for well-preserved works. They do create a protective film but can slightly darken or change the color of pastels. If used, apply in very light layers, testing on scrap first. Museums avoid fixative unless necessary. (By contrast, artist-grade adhesives like those mentioned above can be removed later, which is preferable for conservation.)

  • Tear repair:  Tears and punctures in the paper can be mended from the back with Japanese paper and wheat-starch paste. This reinforces the support and prevents future tearing. After mending, the entire sheet can be humidified and flattened by a professional to remove creases.

  • Surface cleaning:  Dry surface cleaning (soft brushing or gentle erasers) may remove loose dust, but must be done very carefully. Never use water or solvents on pastel – the media will smear. Basic maintenance is limited to dusting with a sable brush under magnification; any stains or adhesive residue require conservators’ attention.

In all cases of repair, the action of a trained paper conservator is recommended. They will stabilize the paper and pigment using reversible, archival methods. As Icon notes: “Consulting a conservator” is advisable when damage has occurred, since professionals can “stabilize [paper and image] so that their deterioration is slowed”. Poor repairs can cause bleeding, discoloration, or loss of image – preserve the original media whenever possible.


Dutch Case Studies and Guidelines

In the Netherlands, heritage institutions have highlighted the special care needed for pastels. The Rijksmuseum in Amsterdam undertook a major project (2007–2013) to conserve over 100 pastel drawings by artists like Liotard and Degas. This project documented how past exhibition conditions (variable light and humidity) had damaged the collection. The conservators found that proper framing and consistent climate were essential to preservation. Their work underscores global best practices: frame pastels in a sealed, buffered environment and avoid fluctuations.

Dutch researchers are also investigating paste transportation risks. A Delft University study (in collaboration with the Rijksmuseum and the Cultural Heritage Agency of the Netherlands) is quantifying how vibrations dislodge pastel pigment. This responds to the finding that even small movements are hazardous – as one report warns, pastels are “fragile… [with] each movement [posing] a risk". For home collectors, this means extra care when moving or shipping pastel artworks (pad them well, avoid rattling crates).

Finally, Dutch conservation bodies (like the Rijksmuseum Conservation Department and Rijksdienst voor het Cultureel Erfgoed) generally follow international standards for works on paper. Recommended readings include ICOM-CC and CCI guidelines on paper conservation, which stress climate control, high-quality framing materials, and minimal handling. In practice, artists and collectors in the Netherlands should adopt the same precautions as recommended worldwide: low light, controlled RH, museum-grade framing, and professional advice when needed.


Sources: Authoritative conservation guidelines for works on paper were used, including the Canadian Conservation Institute, Icon (UK), and Conservation Center for Art & Historic Artifacts. Case studies and museum programs (Rijksmuseum, Norton Simon) provide practical examples. Manufacturers’ data were referenced for material properties (Pastelmat, pastel pencils). Together these resources inform the recommended practices above.


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