Our team surveyed 107 preservation professionals who prepare and care for feathered objects to determine if there is a consensus about preferred dry-cleaning techniques and tools. It did not come as a surprise that vacuum cleaners in combination with a variety of brushes are most commonly employed both to remove dust from and simultaneously restore the natural physical form of the feather vane (fig. 1). Brushes can be used to wipe off dust and loose dirt or to gently push it into a vacuum; or a brush can be attached directly to a vacuum nozzle to clean.
1. Sheep hair, Hake brush
2. Synthetic Kolinsky Sable brush (Stroke)
3. Synthetic Kolinsky Sable brush (Angle Shader)
4. Synthetic brush (Angle Shader)
5. Synthetic grainer brush
6. Pure Badger hair brush
7. Pure Badger hair brush
8. Blue squirrel hair brush (Sacamena)
9. Black goat hair brush
10. Blue squirrel hair brush (Sacamena)
11. Black goat hair brush
12. Synthetic Kolinsky Sable fan brush
13. Synthetic fan brush
14. Chicken feather brush
15. Owl wing
©AMNH/R.Riedler
In the survey responses, some conservators strongly objected to the use of brushes on feathers, as some bristles are too stiff and unzip the vane. In extreme cases, they can break off barbules. Brush strokes can also push or smear loose particulates further into the three-dimensional feather structure before they can be sucked up by the nozzle of a vacuum cleaner.
To brush off dust is not always an easy task!
Here is a breakdown of some of the tools that were identified in our survey.
Animal Hair Brushes
Some respondents indicated that they prefer specific brush shapes for certain tasks (i.e. fan shaped brushes for dust and dirt removal), while others favor brushes of a certain color (i.e. white brushes to track the progress of dirt removal). Survey respondents agreed that they aim to use only very soft brushes to dry clean feathers, usually made of squirrel, sheep, goat, or sable hair (see softness ranking).
Here are the characteristics of some of these hairs:
Kolinsky sable: Some of the highest quality artist brushes are made using the hair of a type of Siberian weasel called a kolinsky or kolonok (Mustela sibirica). The hairs of one tail from the winter fur of the male weasel is the source for three of the finest brushes; number 8. Though globally the population of Mustela sibirica is understood to be large and stable, it is protected under CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) and other legal statutes in a handful of specific countries. These protections limit the quantity of US import and affect cost. The hair itself has directional interlocking scales, which increase the surface area and the strength of the hair. The color is red with dark tips.
Synthetic: Synthetic alternatives for Kolinsky sable brushes are widely available on the market. In general, it is a good idea to check that the ends of the hairs of synthetic fiber brushes are tapered (extruded) instead of cut, since the latter can make them abrasive. Synthetic brush hairs are usually made of nylon, polyester, or a blend of the two. The nylon component is responsible for the smooth finish, while the polyester component gives the hair stiffness and allows it to tolerate higher temperatures.
Squirrel: Squirrel hairs are very thin with pointed tips and a uniform diameter. The innermost layer of the hair (medulla) is filled with air pockets, allowing it to retain large quantities of water. The hairs have little to no spring, but their softness makes them perfect for picking up ultra-thin gold leaves without causing damage.
Most squirrel hair used for brushes comes from Canadian populations of North American red squirrels (Tamiasciurus hudsonicus) and Russian populations of Eurasian red squirrels (Sciurus vulgaris). Eurasian squirrel hairs vary in color depending on the areas in Russia from which they are sourced (i.e. brown-black from Kazan, blue-black from Sacamena, and gray-brown from Talahutky). The Eurasian red squirrel is protected in most of Europe (IUCN Red list categorizes it as a species of “least concern”).
Badger: Badger hair varies greatly in softness, pliability, and color. Lower quality badger hair brushes are made from hair from the underbelly, which is stiffer. Higher quality badger hair is finer and more pliable. The cellular structure of the medulla is amorphous, allowing the hair to retain large quantities of water.
Because badgers are a protected species in North America and most of Europe, all commercial badger hair comes from mainland China. Although it is legal to trade badger hair, some companies have stopped sourcing it out of ethical concerns. The European badger (Meles meles) is protected in most of Europe (IUCN Red list categorizes it as a species of “least concern”)
Goat: Goat hair can be black or white and is very soft and absorbent. The hairs have no spring, but each has a fine point. The hair surface has scales with small pockets which allow liquid to be trapped and held. The best goat hairs for brush-making are taken from the breast of the goat.
Sheep: White sheep hair is most commonly used for Hake brushes. The hairs are boiled to straighten them – however, they remain somewhat wavy. The hair resembles goat hair in behavior.
Alongside synthetic brushes, soft goat or sheep hair brushes are a good alternative to those made with hair from protected or wild animals. As a by-product of the food industry, goat and sheep hairs are more sustainable. The size and shape of the best brush will depend on the size, shape, and condition of the feather to be cleaned and the proposed cleaning treatment. Brushes come in various shapes and sizes: round, pointed round, flat, bright (flat with edges curved inward at the tip with short hair), filbert (a flat and oval-shaped end with medium to long hairs), fan, and angled. In preliminary qualitative testing, we liked flat soft brushes for removing fine dust and fan shaped brushes for removing fibers and larger particles from the feather surface.
Feather brushes and owl wing feathers
Some survey respondents who work with bird taxidermy recommended the use of feather brushes or owl wings for cleaning dust and loose dirt from feathers. The primary wing feathers of owls, referred to as flutings or fimbriae, have a comb-like leading edge and are particularly soft—traits that make them well-suited to cleaning feathers. Feather brushes have a long history in Europe and Asia and have been used in medieval manuscript painting, contemporary calligraphy writing, and Sumi-e painting.
However, owl wings are not readily available and most owls are protected species. Chicken feather brushes are an acceptable substitute. The feathers come in various shapes and can be easily made into brushes and their edges modified or bought premade in specialized art supply shops, e.g. feather sweepers intended to remove eraser dust and debris from artwork (DELETER™ Feather sweeper).
Thanks for reading our run down of bristles and brushes. Let us know which you prefer and why!
In the next post, we will discuss vacuums and vacuum attachments.
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