For as long as artists have worked with brushes, pigments, and varnish, they have also experimented with ways to correct, clean, and reclaim their surfaces. Much of that experimentation has been harmless; some of it has been ingenious. But a surprising number of seemingly practical shortcuts (those “household hacks”) passed around in workshops, online forums, or studio gossip…turn out to be chemically catastrophic.
From the historic use of bread to clean paintings to the modern deployment of oven cleaner and glass spray, the impulse is always the same: to find a simple fix that works and works well. Yet as conservation science has matured, it has revealed a consistent truth. The materials that make a home shine are rarely the ones that should, if longevity is a concern, be applied to your artwork.
The Bread Solution That Went Stale
Before conservation laboratories and stable synthetic tools existed, restorers reached for what they had. One of the oldest examples, believe it or not, was soft bread. Eighteenth- and nineteenth-century manuals often recommended the crumbs of white bread as a way to remove smoke or surface dirt from varnished paintings. Fresh bread, soft and slightly adhesive, behaved like a primitive sponge. Pressed lightly onto a painting, it conformed to texture and seemed to lift grime without scratching. Even into the mid-twentieth century, the practice persisted in European museums, where bread crumbs or bread “pulp” were sometimes used as the first stage of surface cleaning.
The method’s appeal was practical. Bread was flexible, cheap, and easily replaced. Before vulcanized rubber or micro-abrasive pads were available, they offered a controlled way to pick up soot or dust. It worked (or appeared to) because it mimicked mechanical cleaning with minimal pressure.
Modern conservation science has since shown that this visual success concealed multiple hazards. You see, bread is mostly starch and sugar. When pressed against paint or varnish, minute residues of these carbohydrates remain, attracting moisture and providing a growth medium for mold and bacteria. Under magnification, these deposits are visible as discrete granules lodged within the surface layer. In humid environments, they can swell, discolor, and sometimes, even oxidize, producing yellow or brown patches.
Bread also contains small amounts of protein and lipid from flour and yeast, which can adhere to matte paint or absorbent grounds. Over time, these residues form a brittle organic film that not only embrittles but can also darken. The soft crumb that once looked harmless can also abrade friable (easily crumbled) pigment or chalky surfaces, particularly near cracks or cupped paint. In addition, static charge from rubbing crumbs across varnish tends to attract soot rather than remove it, embedding dirt more firmly in surface irregularities.
By the 1970s, analytical studies at the National Gallery, the Courtauld Institute, and the Canadian Conservation Institute confirmed what intuition could not: bread was leaving behind measurable contamination. Today, it is classified as obsolete and unsafe. Conservators now rely on vulcanized rubber sponges, cellulose-filled cleaning pads, or pH-tested aqueous gels that remove loose grime without depositing reactive material.
The story of bread illustrates how a practice born of necessity can survive by habit long after better evidence exists. Bread cleaning seemed gentle because it felt familiar. Only under the microscope did its real chemistry become visible.
Easy-Off and the Alkali Illusion
In our own century, the tradition of improvised cleaning continues, often amplified by social media. Recently, an artist posted a video showing how to strip oil paint down to the “bare canvas” using heavy-duty Easy-Off oven cleaner. The claim was that the sodium hydroxide in the product would dissolve the paint but leave the acrylic gesso ground unharmed, since “alkalis only affect organic materials” and acrylic was presumed to be inorganic.
Every part of that reasoning collapses under chemistry.
What may be surprising to some, in scientific terms, “organic” means carbon-based, not natural or biological. Acrylic polymers—derived from acrylic and methacrylic esters—are built entirely on carbon–carbon and carbon–hydrogen frameworks. They are synthetic, but they are still organic compounds. To call them “inorganic” is to confuse the common colloquial usage of a term with that of chemistry.
Sodium hydroxide (NaOH), when dissolved in water at high concentrations, produces a solution with a pH near 14. In such alkaline conditions, its reactivity is broad and largely non-selective. In aqueous solution, the high concentration of hydroxide ions (OH⁻) facilitates the hydrolysis of many chemical linkages, especially esters, found in both natural and synthetic materials. In both oil paint and acrylic binders, the hydroxide ions cleave ester linkages: in oils, this results in saponification—producing soaps and glycerol—while in acrylics, it degrades the polymer backbone, shortening molecular chains and often leaving a chalky, friable (easily crumbled) residue. This reaction, alkaline hydrolysis, is documented in studies by Down (1981, CCI Notes 10/12), Ploeger (2006), Ormsby and Learner (Tate/GCI 2009), and Novak and Ormsby (2023).
Even worse is that the chalk component of acrylic gesso is vulnerable. Calcium carbonate reacts with sodium hydroxide to produce sodium carbonate and calcium hydroxide, an additional caustic compound that permanently raises the pH of the ground.
CaCO3+2NaOH→Na2CO3+Ca(OH)2
Unfortunately, a canvas beneath fares no better if exposed. Cellulose undergoes alkaline hydrolysis, shortening its polymer chains and weakening its tensile strength, as Barrow’s classic Smithsonian work on paper degradation first documented in the 1960s.
These processes begin immediately upon contact. The absence of visible damage does not mean safety; it means invisibility. The artist in the aforementioned video did attempt to “neutralize” the alkali with lemon juice, but that reaction merely adds citric acid and moisture, creating secondary salts, and even localized heating. It’s important to note here that the underlying polymer and fiber damage cannot be reversed by surface acidification.
Acrylic gesso, though often described as “plastic,” uses the same binder chemistry as acrylic paint. The presence of carbonate fillers makes it more, not less, sensitive to strong bases. After treatment with an oven cleaner, what looks like clean, bare fabric is actually a chemically scorched support with reduced elasticity and altered surface chemistry. Paint applied over it may adhere initially, but will face significantly increased chances for delamination as the weakened film continues to deteriorate.
When presented with all of these facts, the artist retreated to an argument that “no formal study has tested Easy-Off on acrylic gesso.” I don’t think I need to tell you that this is not exoneration; it is precisely why conservators avoid such treatments. Chemistry does not depend on brand names to predict outcomes. If the reactive groups and conditions are known, the degradation pathways are already established. Sodium hydroxide is known to attack oils, acrylics, carbonates, and cellulose. The conclusion does not change because the bottle says “oven cleaner.”
The Windex Shortcut
Another modern habit making the rounds on forums and even some classrooms is the use of Windex or similar glass cleaners to “clean” a painting surface or to fix “beading” issues when fresh paint seems to repel a layer beneath. The reasoning is familiar: the product removes grease, dries fast, and makes the surface look fairly receptive again. The problem here is that what works beautifully on glass is, in fact, chemically hostile to a painting.
Commercial glass cleaners are basic aqueous ammonia solutions containing alcohol, surfactants, dyes, and fragrances. Each of these ingredients presents a risk to oil and acrylic films.
Ammonia (NH₃) dissolved in water establishes an equilibrium with ammonium (NH₄⁺) and hydroxide ions (OH⁻), yielding a weakly alkaline solution with a pH typically around 11. In oil paint, this mild alkalinity promotes soap formation by reacting with metal ions in pigments or driers. In acrylic films, hydroxide ions can initiate the same type of ester hydrolysis seen with stronger base materials, (“stronger” meaning they have a higher concentration of hydroxide ions), such as oven cleaner, accelerating surfactant movement, and softening the polymer surface.
The alcohol content—usually isopropyl or ethyl—adds another layer of hazard. Alcohols are efficient solvents for natural resins and can partially dissolve or dull synthetic polymers. They penetrate paint films rapidly, carrying alkaline residues into deeper layers and altering the internal cohesion of the polymer matrix. In oils, they desiccate the surface, leaving it brittle (note: A desiccated oil surface is one that has been chemically “over-dried” by alcohol exposure, losing vital plasticizers and moisture, which can result in a film that is more brittle, matte, and structurally weaker.)
It’s a deceptively clean look masking a compromised paint film.
Surfactants, the detergents that lower surface tension, create the illusion of improvement. A film that was once beading suddenly wets evenly because detergent residues remain. Those residues are hygroscopic (absorbing or releasing moisture to maintain equilibrium with ambient humidity), attracting moisture and airborne dust. Over time, they can form sticky, hazy films that interfere with later adhesion or varnishing. The cleaner may appear to solve the problem while actually embedding a potential new one.
The smell and familiarity of Windex encourage the perception that it is mild, but in conservation terms, it falls squarely into a class of polar solvent/weak base systems considered unsafe for all paint types. Every major conservation reference—Feller’s Artist’s Pigments, Down’s CCI Notes, Ormsby and Learner’s Tate/GCI studies, and the CAMEO materials database—lists ammonia and alcohol mixtures as incompatible with both oil and acrylic media.
The “beading” issue these cleaners are meant to cure is almost always a symptom of contamination by oil, wax, or migrated surfactants, not a lack of cleanliness. Proper correction requires identifying and isolating the contaminant, not blanket application of an industrial detergent.
Vaseline Brush-Shaping
Yet another persistent studio hack recommends applying petroleum jelly (Vaseline) to oil-painting brushes after cleaning to help them keep their shape. However, both conservation practice and authoritative technical sources, such as Ralph Mayer’s The Artist’s Handbook of Materials and Techniques and Mark Gottsegen’s The Painter’s Handbook, do not endorse this, and their guidance runs counter to it. Petroleum jelly is a non-drying, hydrocarbon-based grease that does not oxidatively polymerize the way drying oils do. Applied to bristles, it remains as a soft film that readily captures and retains dust and airborne contaminants, can migrate into subsequent paint layers, and may interfere with the oxidative crosslinking of drying oils if residues are left behind.
Material “gurus” like Mayer and Gottsegen instead stress immediate, thorough cleaning (with solvents as needed, followed by a mild soap and warm-water wash, ending with a gentle manual reshaping and air-drying.) At our Academy (ÀNI Art Academies Waichulis) also reinforces this approach, recommending brush-tying for medium and high-resistance brushes (wrapping damp string around the ferrule and hair bundle while drying) for those seeking additional shape control, rather than introducing any non-curing substance. Even manufacturer guidance (e.g., Winsor & Newton) flags vaseline/“petrol” tricks as unreliable and not recommended for brush protection.
In short, using Vaseline to preserve brush shape isn’t a clever hack but a chemically unsound shortcut that risks both the brush and the integrity of future paint films.
Why the Studio Keeps Repeating History
Bread, Easy-Off, Windex—each of these examples arises from the same human impulse. Artists are problem solvers. Faced with resistance on the surface, we reach for tools that have worked elsewhere in life. The difficulty is that a superficial fix validated by a certain level of “visual success” is not the same as chemical success. Bread seemed safe because it was soft. The oven cleaner seemed effective because it revealed white fabric. Windex seemed harmless because it made glass sparkle. All of them “worked,” in the sense that they produced a visible change. In every case, what looks like immediate improvement conceals a significant potential for long-term degradation. The polymer chains can shorten, the fillers can convert (minerals once considered inert can change their chemical form under inappropriate conditions), the cellulose can weaken, or the residues can attract moisture and dust. Worse yet is that the damage is often cumulative, not instantaneous. It is the quiet kind of failure that only appears years later when cracking, dulling, or delamination occurs. The same pattern shows up in tool care: a dab of household grease can make a brush look disciplined today while seeding tomorrow’s adhesion and dust problems.
Better Practices
Conservation laboratories now rely on materials specifically tested for compatibility, pH, and reversibility. Dry cleaning with a soft, natural-hair brush or a microfiber cloth removes loose dust without introducing a new chemistry that can lead to the issues presented here. For more stubborn deposits, dry-cleaning pads filled with inert cellulose powder or vulcanized rubber sponges are preferred. Reusing a support should involve mechanical removal of paint—careful scraping or sanding—followed by measures appropriate for the intended materials. Any solvent or aqueous cleaning system should be informed by appropriate literature and, ideally, guided by an experienced conservator.
At its core, the problem with household products in the studio is a mismatch of purpose. These formulations are engineered to dissolve, strip, or polish materials that are designed to withstand aggressive chemistry—metal, glass, ceramic—not the hybrid organic–inorganic composites of paintings. The very efficiency that makes them valuable in a kitchen or garage can also ensure that they are destructive in a studio.
Artists today have access to better information than ever before. Conservation research, polymer science, and archival chemistry have made it possible to predict how materials age and interact. The challenge is not ignorance but translation—bridging the gap between what is known in laboratories and what circulates as casual advice among painters.
The guiding principle is simple: if you don’t know what’s in it, don’t rush to put it on your work.
Whether the tool is a loaf of bread or a bottle of oven cleaner, understanding its chemistry is the best way to know whether it belongs in the kitchen cabinet or in the studio.
Selected References
Down, J. L. (1981). The Effects of Alkali on Acrylic Emulsion Paints. Canadian Conservation Institute Notes 10/12.
Ploeger, R. (2006). The Effects of Aqueous Immersion on the Chemical, Visual and Morphological Properties of Artists’ Acrylic Paints. Library and Archives Canada.
Feller, R. L. (Ed.). (1986–2007). Artist’s Pigments: A Handbook of Their History and Characteristics. National Gallery of Art.
Ormsby, B., & Learner, T. (2009). Tate/GCI Research on the Cleaning of Acrylic Paintings.
Novak, M., & Ormsby, B. (2023). Poly (Vinyl Acetate) Paints: A Literature Review of Material Properties, Ageing Characteristics, and Conservation Challenges. Polymers, 15(22).
Ward, G. W. R. (2008). The Grove Encyclopedia of Materials and Techniques in Art. Oxford University Press.
Ziraldo, I., Watts, K., Luk, A., & Lagalante, A. F. (2016). Studies in Conservation, 61(sup1), 45–54.
Mecklenburg, M. F., & Tumosa, C. S. National Gallery of Art Conservation Research Technical Bulletins.
Barrow, W. J. (1960s). Physical and Chemical Properties of Cellulose and Paper. Smithsonian Institution.
CAMEO Database, entries “Acrylic Resin” and “Alkali.”
Gamblin Artists Colors. (n.d.). Solvent-free oil painting (studio safety). Retrieved November 2, 2025, from Solvent-Free Oil Painting
GOLDEN Artist Colors. (2019, September 13). Cleaning brushes without solvents. Just Paint. Retrieved November 2, 2025, from Cleaning Brushes Without Solvents | Just Paint
Museum of Fine Arts, Boston. (2022, July 26). Petrolatum. CAMEO: Conservation & Art Materials Encyclopedia Online. Retrieved November 2, 2025, from https://cameo.mfa.org/wiki/Petrolatum
Smartermarx (Waichulis, A.). (2017, February 6). Resource: Cleaning and tying paintbrushes—Materials. Retrieved November 2, 2025, from RESOURCE:Cleaning and Tying Paintbrushes
& Newton. (n.d.). How to protect brushes when using Art Masking Fluid. Retrieved November 2, 2025, from https://www.winsornewton.com/blogs/guides/protect-brushes-art-masking-fluid
And a special thank you to friend and colleague Maneesh Yadav for making sure my claims regarding the chemistry are clear and accurate.
