Tips for Maintaining the Luster, Nurturing the Character and Ensuring the Longevity of Your Home’s Leather Furniture
In our series “Caring for Artisan or Antique Furniture,” we at Living Deep will explore the best ways in which to protect heritage furniture. We will discuss how to prevent damage, and how to address that damage if it occurs. Our goal is to provide in-depth information about the preventive and remediation care of heritage furniture. We hope to help owners protect each piece so it can live as long as possible in its home. We begin our series with “Caring for Artisan or Antique Furniture Upholstery: Leather Edition.” The first step to preserving antique, vintage or artisan-made furniture is to maintain a proper environment for each piece. This means limiting extreme highs and lows in relative humidity and temperature. It also means preventing spills wherever possible and cleaning as often as necessary to prevent pests. Issues of pests and response to changes in climate are more common with organic materials used in upholstery, particularly suede, leather, wool and silk.
Prevention is the best method of preservation. It requires little intervention and will keep each special piece in your home in its best condition -- barring disaster. However, spills and weather events do happen and these may impact the condition of your furniture pieces -- just as art might. Contemporary custom- or artisan-made and vintage or antique furniture upholstery all require some level of upkeep and care. However, these methods might differ rather significantly from the care of pieces not intended for lifetime use. Follow below for our tips on caring for leather pieces you intend to keep in your home for many years. Read on to learn what you can do yourself, and when to reach out to a restorer, furniture maker, upholsterer, conservator or other professional.
Identifying Leather Furniture
"It is how leather is processed that determines which of three main categories it falls into aniline, semi-aniline, and protected or pigmented leather." - Abe Abbas, "3 Most Common Types of Leather Used in Furniture," The Spruce
The type of leather which makes up your furniture piece will determine in part how it should be cared for. The performance, quality and longevity of a piece are all affected by the method of preparation of each type of leather. In a recent article for The Spruce, Abe Abbas writes the most common types used in furniture are aniline, semi-aniline and protected leather. Both aniline leather and semi-aniline leather are delicate when compared to pigmented or protected leather, meaning that great care is necessary. Abbas explains that aniline leather is the most prized of the three. This is because it “is the most natural-looking type of leather and retains unique surface characteristics like pores scars.” Rather than being coated, aniline leather is dyed, which leaves behind the original texture and appearance of the hide. Over time, aniline leather will adopt a patina from the oils deposited by users. The absorption of oils over time -- possible because the leather is not coated or painted -- makes aniline softer and more enjoyable throughout its lifetime.
Unfortunately, it is this same sought-after quality that makes aniline leather easily stained. For this reason, those owning aniline leather-upholstered furniture should keep such pieces out of use by young children. They should also be kept away from areas prone to frequent foot traffic. Semi-aniline leather refers to that which combines “the uniqueness of aniline leather” with the consistency of color and durability of a more prepared leather. Semi-aniline leather is typically lightly coated, making it less likely to stain but also less textural than aniline leather. The last type of leather used frequently in furniture upholstery -- and least common in artisan or antique furniture -- is protected or pigmented leather. Protected leather looks the least like natural hide, but is most durable when compared to the other two. Protected leather, writes Abbas, “has a polymer surface coating containing pigments,” making it the least sensitive to moisture, temperature and contact damage. However, this coating obscures the grain of the leather.
Condition Issues to Be Aware Of When Caring for Leather Furniture
Temperature and Relative Humidity
"In most cases, it is ambient conditions that will lead to the cracking of leather—extreme temperatures and lack of moisture." - Kristi Kellogg, "How to Clean Leather Couches, Chairs, and Other Furniture," Clever/Architectural Digest
The NPS publication “Curatorial Care of Objects Made from Leather” explains that the ways in which leather and other organic materials deteriorate are interdependent. While the publication is intended for heritage preservation professionals, it applies to in-use residential leather furniture as well. The NPS brief explains, changes in and high -- or particularly low -- levels of relative humidity and/or temperature can have varied and wide-ranging effects on leather, inviting pests and other biological attacks, cracking or swelling and much more. The brief notes that “temperature changes directly affect a skin or hide's moisture content." Temperature also affects "the rate at which chemical deterioration proceeds, and the object's susceptibility to biological infestation.” Leather may also crack in extremely low temperatures -- or in extremely low relative humidity conditions.
Relative humidity fluctuations can also cause horrific damage to leather objects, one manifestation of which is red rot. The article “What is Red Rot Leather and How to Treat it” from Preservation Solutions explains that red rot occurs in vegetable tanned leather. It occurs in such leather that has reached “temperatures beyond what it can handle [or] has been exposed to high relative humidity." It may also occur if the leather has been affected by environmental pollution. Lastly, red rot can occur if the leather has been stored in poor or unregulated conditions for an extended period of time. If red rot is ever found on leather furniture, it will likely need to be treated by a professional. However, the issue is more common with smaller items that are repeatedly fed oil. These might include luggage and book covers. Maintaining consistent and appropriate temperature and relative humidity levels in the home is the first step in caring for your leather furniture.
"Under certain temperature and humidity conditions, [mold] can easily grow on leather and feed causing various undesirable effects [like] stains which can be grey, green or black and may be permanent in light color leathers." - "Mold and its impact on leather," Impactiva
Lack of cleanliness can also contribute to a variety of issues, particularly destruction from pest infestation. The NPS brief notes that “a great variety of biological organisms are attracted to skin and hide.” Sadly, these organisms often create “irreversible damage or total destruction” when exposed to leather for too long a period of time. When leather is cleaned poorly, inconsistently or infrequently, “beetles and clothes moths…[and] silverfish and cockroaches” may attack the leather, though this is more common in wool, fur and untreated skins. Even when infestations are addressed and furniture pieces are successfully rid of their unwanted inhabitants, the damage is often irreversible. Pests may leave behind stains from frass in addition to chewed holes, acidic burns and other cosmetic and stability condition issues. “Molds and occasionally bacteria” may also form on leather and begin to deteriorate the product. This may result in the production of “organic acids and enzymes that bleach and stain” the leather. Again, maintaining a proper climate and brushing away debris will keep your leather in better condition than simply leaving it alone.
Tips for Caring for Leather Upholstery in Good Condition
Treating leather at home on one’s own may be appropriate if the piece is of no historical, sentimental or monetary value. However, treating vintage, antique or artisan-made leather is often best done by a professional, or with the advice or guidance of a professional. There are currently competing opinions in professional fields whether leather should be “fed” or conditioned regularly or just when the piece demonstrates need. These two arms are best named “interventive” and “preventive,” as described by Vicki Dirksen. In her article “The Degradation and Conservation of Leather” for the UCL Journal of Conservation and Museum Studies, Dirksen explains the two approaches. Dirksen writes that the older method of caring for leather objects “uses the application of dressings as a means of prolonging [their] life.” However, newer philosophies move towards “a more preventive approach,” focusing on improving storage, display and use. There are debates on whether owners should conduct invasive cleanings or treatments of their own. However, it is generally accepted that dry cleaning leather -- or cleaning with light and innocuous moisture -- is acceptable at home. This is because such a type of cleaning is largely considered preventative. If severe damage has occurred, reach out to a local professional -- or if possible to the artisan who created the piece in question.
Establishing a Proper Environment
"Heating vents, radiators, and space heaters can dry out and ruin leather furniture with prolonged exposure. In addition, exposure to sunlight can fade and damage your leather furniture as well and you will end up with minimally discolored patches on the furniture." - Sarah Aguirre, "5 Leather Furniture Mistakes," The Spruce
Light exposure, relative humidity and temperature should all be controlled to ensure that leather furniture remains a fixture in the home for many years. Dirksen explains that -- according to the Canadian Institute for Conservation -- relative humidity should be maintained within the home at a “level in the range of 45% to 55%,” never reaching 65% which is the floor at which mold begins to grow. Leather furniture owners would do best to maintain the temperature in their homes between “18 degrees Celsius to 20 degrees Celsius.” This translates to 62 to 68 degrees Fahrenheit. Of course, this temperature range is typically considered slightly uncomfortable for human inhabitants and will likely not be stuck to over time. As such, try to keep the temperature in one’s home below 76 degrees Fahrenheit (ca. 24 °C) whenever possible. Avoid placing leather furniture directly in the pathway of air conditioner or heating vents, radiators, lamps or other potentially dangerous outlets.
Conducting Safe and Effective Cleaning
"Under normal usage/conditions, regular dusting and vacuuming in crevices or along the bottom are all that is necessary to clean leather furniture." - Jessica Bennett, "The Best Ways to Clean and Care for Leather Furniture and Apparel," Better Homes & Gardens
To carefully clean your leather furniture at home, follow Jessica Bennett’s instructions in her article for Better Homes & Gardens. Bennett offers a conservative approach to cleaning leather in good condition. Good condition refers to leather which is not excessively cracked or flaking. Neither should "good condition" leather be subject to biological or other attacks like mold, red rot or pest infestation. Bennett writes that under “normal usage/conditions, regular dusting and vacuuming...are all that is necessary to clean leather furniture.” If there are stains or dust buildups, Bennett suggests dusting “your leather couch or chair with a microfiber cloth that's just barely dampened.” The cloth should only be moistened with water. A vacuum “with a stiff-bristle [but not aggressive] upholstery brush” can then be used over the cushions. Finally, Bennett suggests “breaking out the crevice tool [of your vacuum or kit] for corners and other hard-to-reach areas.”
If you find a stain or deposit that cannot readily be removed with light moisture or pressure, leave it be and contact a professional. Unfortunately, as the Smithsonian Museum Conservation Institute brief “Stain Removal“ notes, “stains disfigure clothes and home furnishings." It is "desirable to remove them, especially if the stains stiffen or corrode” what exists beneath them. This is especially true of acidic deposits or stains -- such as frass from insects. Whatever you do, do not try home remedies with corrosive substances on delicate leather. Avoid using common household cleaners like acetone, which can destroy the grain, tanning and overall fiber structure of the leather. Also avoid ammonia, chlorine bleach, hot water, club soda, hydrogen peroxide, lemon juice, white vinegar, oxalic acid and salt.
By establishing a stable environment, cleaning messes and gently dusting now and again, you can rest easy knowing your leather furniture is well cared for and will last a lifetime.