All of my brushes are carefully hand-crafted using local bamboo, natural hairs, tanned leather for the hanging straps, and waxed Irish linen threads for the decorative wraps on the handles. All brush heads and straps are set into the handles using epoxy resin for a nearly indestructible weld. With nominal care they should last many years.
The decorating brushes are made from a variety of hairs - Gray and Red Squirrel tail hair, and Eastern White Tail Deer (BuckTail) for the "production" brushes. I have also started using tail hair from the Stone Marteen - a VERY supple and soft hair that works well with a variety of thickness materials. Some of the specialty brushes use Ringtail Cat Tail hair - a great hair but VERY expensive on the market right now.
The squirrel tail hairs are quite fine and soft, and work very well for thin to medium thickness materials. They are relatively absorbent, and are excellent for decorating with underglaze pigments, oxides, and thinner glazes. They also behave quite nicely with calligraphy inks and with watercolor.
Probably my new favorite brush hair for all around use is the Stone Marteen tail hair. It is long and supple and works great for thin to medium thickness materials in ceramics as well as inks and watercolors.
The BuckTail and Hog Tail brush hairs are much coarser and are excellent for thicker materials (think tomato soup and thicker) like slips and thick glazes. They do not work very well with thin materials as they drip quite freely with thin mixtures.
Slip Brushes: The brown slip brushes are made using horse tail hair, and have a slight coarseness that allows for medium to strong “hakame” brush marks when applying slips. This obviously depends upon the thickness of slip you are using, and your brush “methods”.
The white slip/glaze brushes are made from Asian goat hair (many commercial Chinese/Japanese slip brushes use this) and are quite soft and silky feeling. They apply slips with almost no marks, or a fine ‘hakame” texture. These goat hair brushes are also nice for applying large areas of glaze, either directly onto bisqueware, or for glaze over glaze.
The Broom Corn brushes are great for making very strong and distinct Hakame marks and also are quite good for applying subtle textures to soft leather-hard clay.
Brush care: Wash them well after using to get out all slip/underglaze etc. Leaving the clay materials in the hair will dry them out and makes the hairs brittle. After washing hang them by the strap to dry if possible, or lay them down flat. Never dry them "upside down" with the hairs up - as this lets all the water run into the handle area and weaken the bamboo and head connection.