When designing a paintbrush, several aspects must be taken into consideration when choosing a filament. The main ones are :
1. Filament resistance to chemical components
2. Good filament mechanical performances (stiffness, bend recovery)
3. Best mechanical characteristics value ratio
4. Tip capability to distribute paint evenly
The first three characteristics drive to a specific raw material, which is polyester PBT.
The fourth aspect has been interpreted by STP with 2 products: hollester and polysair Multi channel STP filaments.