Sponges and cloths used to clean feathers: an ab(/d)sorbing post

Into the mid-20th century, bird skin and bird taxidermy were cleaned with cotton cloth or wadding and natural sea sponge. In fact, the sea sponge was used for body and household hygiene going back to ancient Greece (Greek: spongos). Today, a large variety of synthetic sponges and cloths are available to conservators and are commonly used during treatments. 

Survey says that, of 90 responses to questions about using sponges and cloths for feather cleaning… 


Here is a sampling of sponges and cloths mentioned in the survey and some that the IMLS team have been experimenting with for dry and wet cleaning soiled duck and turkey feathers. 

©AMNH/R.Riedler

1 Sofft tools sponge | isoprene rubber and styrene butadiene rubber 
2 Soot sponge | vulcanized natural rubber with additives 
3 Cosmetic sponge | polyurethane ether or ester with additives OR styrene butadiene rubber with additives 
4 Hydrophilic sponge | polyvinyl alcohol (PVOH or PVA)
5 Vellux® | polyurethane foam with nylon filament pile 
6 Microfiber Cloth | suede 
7 Velvet | silk 
8 Velvet | polyethylene (PE) and lycra 
9 Evolon CR | spun-bonded 70% polyester and 30% polyamide (nylon) blend non-woven textile 


However, as our feather cleaning community survey shows, these materials are more cautiously applied to feather cleaning than brushes and vacuums. Sponges and cloths are effective cleaning tools, but generally shouldn’t be used before feathers have been vacuumed gently to reduce the number of loose particulates on the surface. Moving soil around instead of picking it up can disrupt the barbs and redeposit dirt onto the feather surface in ways that make it harder to remove. Redeposition can be further limited by promptly replacing dirty sponges with clean ones during treatment. 

Responses to our survey also highlighted the importance of the pressure and technique applied when cleaning and the condition of the feather when sponges or cloths are used. Out of 47 respondents who use/have used sponges and cloths on feathers, a little less than half reported that they have observed damage after dry cleaning with sponges and about a quarter reported damages after dry cleaning with a cloth. Deformation and/or breakage of barbules, loss of gloss, abrasion, and residues are the most common reported negative effects of cleaning with sponges and cloths directly. Many respondents pointed out that, in addition to the damages, the bird will be left with unnaturally groomed feathers if tools are not properly applied.  

Rather than rubbing or rolling, it is recommended that sponges be dabbed gently against the feather surface. Some professionals highlighted the benefit of a simultaneous grooming and cleaning effect. Some use sponges only on larger contour feathers in good condition and on quills (the rachis and calamus). Others utilize sponges only in cases where there is heavy soiling. Certain sponges are applied dry, while others are moistened with distilled water or ethanol, depending on the characteristics of the surface dirt.

In her thesis, textile conservator Allison Anderson (Anderson 2016) found that, for cleaning textiles, the physical characteristics of a sponge are very important. She found that sponges with the smallest cells are more effective than those with larger cells. When sponges are viewed under magnification next to the feather vane, the reasons for this become clearer. Differences in the structure and relative cell size of various sponges affects the amount of surface contact between sponge and feather during cleaning, and thus both the damage and cleaning potential as well.

COSMETIC SPONGE | Cosmetic wedge, beauty blender, etc.

Composition: Styrene butadiene rubber OR Polyurethane foam, may contain additives such as Tinuvin® as alkaline fillers (e.g. calcium carbonate) and antioxidants.  

  • Known to leave residues, particularly if unwashed  
  • Can wash & reuse 
  • Used for both dry and damp cleaning  

SOFFT TOOLS | Micropore sponge developed for PanPastel™

Composition: mixture of isoprene and styrene butadiene rubber. 

  • May leave residues 
  • Can wash & reuse   
  • Used for dry cleaning 

HYDROPHILIC SPONGE | Polyvinyl Alcohol (PVA) Sponge, Blitz-Fix, Conservators Sponge™, etc.

Composition: Closed cell polyvinyl alcohol foam 

  • May leave residues 
  • Can wash & reuse 
  • Used for damp cleaning 

SOOT SPONGES  | Wallmaster, Absorene® Dry-Cleaning Soot Sponge (Dirt Eraser), etc.

Composition: Natural rubber contains polyisoprene polymers, predominantly cis-1,4-polyisoprene, and alkaline filler (calcium carbonate) is sometimes added. Vulcanized rubber is usually cross-linked with sulfur. 

  • Known to leave residues
  • Can wash & reuse 
  • Used for damp cleaning 
Top left: Cosmetic sponge (white) | Bottom left: Soot sponge (brown) | Top right: hydrophilic sponge (yellow) | Bottom right: Sofft tool sponge (pink) ©AMNH/R.Riedler

Anderson also found that natural-rubber sponges deposit more residues during cleaning compared to polyurethane (PU) foam. To mitigate possible particulate residues, some conservators follow sponge cleaning with further gentle vacuuming. Some sponges are known to contain additives that one would not want to transfer to the surface during cleaning, so thorough washing prior to use is a good practice.

Conservators in the Anthropology Conservation Lab at AMNH frequently use cosmetic sponges. Prior to use, they are rinsed in a washing machine (without soap/detergent) or in tubs of water and agitated to remove whitening and other water soluble additives. After rinsing, they lay the sponges out on towels to dry. They note that the rinsed sponges are more yellow in color and tend to break down more quickly than the un-rinsed counterparts, but they will not deposit unwanted residues on the surface of feathers or other objects, especially when used during wet cleaning.

Top left: Dust Bunny® Magnetic Wiping Fabric | Bottom left: Microfiber cloth (Suede) | Top right: Vellux® | Bottom right: Velvet (PE & Lycra) ©AMNH/M.Paulson

Cloths recommended for possible dry cleaning use by survey respondents and American Museum of Natural History conservation staff are listed to the right. Any product should be tested closely for potential impact on feathers before use (pending results from our study!).

A concern when using a cloth as a cleaning material is that loose fibers from the cloth can get stuck in feather barbs and barbules. For dry cleaning, synthetic lint-free cloths leave fewer fibers behind. Fiber loops within a cloth can also catch on barbs and move them out of alignment. Cloths alone can also redistribute soiling on different parts of the feather if they become oversaturated or do not effectively trap or attract the dirt. 

The soft bristles of piled fabrics like velvet and Vellux®  can be very effective in loosening dirt particles from the feather vane. A piled weave involves loops or tufts that extend perpendicularly from the surface of the fabric, which allows for greater access to the interstices between barbs than a flat weave. However, care must be taken when applying pressure while using piled cloths to clean. Too much pressure flattens the pile and negates its usefulness!  

Depending on which type of velvet you use, it’s possible that the secondary warps that make the original loops of the pile may not have been thoroughly cut. These missed loops in the pile may catch on the small barbules and displace them, though this is certainly less likely in commercially made velvets.  

Vellux®  has become a fabric of particular interest for cleaning because of its soft slightly structural foam layer and the tiny scale of the nylon fiber pile. The open structure of the foam allows for it to be secured over a vacuum nozzle without significantly impacting the suction strength. 

There is the possibility that thin fibers from any cloth can be loosened and deposited onto the surface, like the particulate residue previously mentioned from sponges. Following up such cleaning with a light vacuuming pass or using a vacuum with the cloth should negate this issue. 

COTTON, WOVEN OR NON-WOVEN | Cotton gloves, fabric, wadding. 

Composition: 100% cotton 

  • Not lint-free!  
  • Can wash & reuse  
  • Used for dry and wet cleaning 

WOVEN MICROFIBER CLOTH | eyeglass and lens cleaning cloths, micro-fiber towels 

Composition: Polyester/polyamide blend or 100% polyester. Fibers are finer than one denier (i.e. one strand of silk). 

  • Lint-free 
  • Can wash & reuse  
  • Used for dry cleaning 

NON-WOVEN MICROFILAMENT CLOTH | Dust Bunny dust cloth, Evolon CR 

Composition: Highly absorbent polyester (70%) and polyamide (30%). Products have similar FTIR spectra. 

  • Lint-free 
  • Can wash & reuse  
  • Used for dry cleaning 

LOW-PILE FABRICS | Synthetic velvet (polyester, nylon, viscose, or rayon), silk velvet (silk and rayon).  

Composition: Varies 

  • Not lint-free  
  • Can wash & reuse  
  • Used for dry cleaning 

VELLUX® | Bead mats, blankets  

Composition: 100% flocked Nylon fibers and closed cell polyurethane foam, terylene polyester webbing.  

  • Lint-free, but possible deposition of other residues remains to be explored 
  • Can wash & reuse   
  • Used for dry cleaning 
Dry cleaning of Scrub Jay mount with Velux foam attached to a vacuum nozzle (left) and Velux foam attached to a spatula (right) ©AMNH/R.Riedler

Cloths (and even some sponges!) can be attached to a vacuum nozzle, using suction to more effectively lift soiling up off the feather and into the cloth. When coupled with a piled cloth like Vellux® , dirt is disturbed by the perpendicular fibers of the pile and then trapped in the weave or webbing of the fabric below the pile. The cloth may get soiled relatively quickly and should be constantly rotated to a clean section to avoid redepositing dust and dirt onto the feather. 


Dry cleaning of Scrub Jay mount with microfilament cloth Evolon CR (left) and Polyester velvet fingerling (right) ©AMNH/R.Riedler

Recommended reading

Anderson, A. M. 2016. Comparison of Dry-Cleaning Sponges Used to Remove Soot from Textiles. Open Access Master’s Theses. Paper 949.University of Rhode Island, USA. 67 pp. https://digitalcommons.uri.edu/theses/949 (15 January 2020)

Brokerhof, A. W., S. de Groot, J. L. Pedersoli, H. van Keulen, B. Reissland, and F. Ligterink. 2002. Dry Cleaning: The Effects of New Wishab Spezialschwamm and Spezialpulver on Paper. Papierrestaurierung, 3(2):13–19.

Casella, L. and Moore, C. 2009. Research on Methods for Cleaning Face-Mounted Photographs. Topics in Photographic Preservation, vol. 13. AIC, Washington D.C. pp. 200-208.

Daudin-Schotte M, Bissch M, Joosten I, van Keulen H, van den Berg KJ. 2013. Dry cleaning approaches for unvarnished paint surfaces. In: Mecklenburg MF, Charola AE, Koestler RJ, editors. New insights into the cleaning of paintings: proceedings from the cleaning 2010 international conference, Universidad Politécnica de Valencia and Museum Conservation Institute. Washington D.C: Smithsonian Institution Scholarly Press. pp. 209–20. [Includes a great chart of unpublished data done by the Cultural Heritage Agency of the Netherlands, p210-11]

Schorbach, S. 2009. Reinigungsschwämme in der Restaurierung—Vergleichende Untersuchung zu Material, Wirkung und Rückständen. [Cleaning Sponges in Restoration—A Comparative Study with Regards to Material, Effectiveness and Conditions.] Zeitschrift für Kunsttechnologie und Konservierung, 23(1): 41–54.

Tsang, J. and Barnes, S. 2017. Capturing Dust: Microscopic Examination of Vellux® Fabric Used in Modern and Contemporary Paintings Conservation by WAAC Newsletter 39(3): 9-12

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