Brushes
Brushes differ in hair type, resilience, absorption, point shape and size; therefore the same brush does not react the same in watercolor, acrylic and oil paint.
Linking shape and fiber to the paint
Round brushes create lines and details, flat shapes create surfaces and edges, and mop or wash brushes carry a lot of water. Synthetic fibers are abrasion resistant and suitable for many water-based media; softer fibers provide controlled washes. For thick paint, sufficient resilience is more important than maximum absorption.
Proper cleaning extends the lifespan
Do not let paint dry in the ferrule, rinse in the direction of the hair and use a cleaner that suits the medium. Carefully reshape the tip and let it dry flat or with the bristles down without putting pressure on the tip. Store dry brushes protected but not airtight when moisture is still present.
Also explore Brushes & Tools · Paint · Cases & Storage for compatible materials and the next step in your project.