Standard hair: Synthetic filament — nylon or Taklon (a tapered polyester fibre engineered to mimic sable's point and snap)
Why not natural hair: Acrylic's alkaline binder and fast water evaporation dry paint directly onto natural hair's protein structure, degrading it over repeated use far faster than oil or watercolour would
Taklon colour-coding: filament colour typically signals stiffness — black (softest, most flexible), gold (mid), white (stiffest) — a genuinely useful at-a-glance system most painters never learn
Shape range: full range available in synthetic — round, flat, filbert, fan, angle — acrylic does not restrict shape the way stiffness requirements do for oil
Fast-drying complication: acrylic dries in the brush itself within minutes if left unattended — this affects brush choice less than it affects brush care (see technique_tip)