Basic knowledge like knowing the basic tools of writings is essential. A good calligrapher is able to fully understand the characters of different brushes. Brushes of soft hair or made of goat's hair is less resilient and elastic than those of hard hair or made of weasel's hair. Different brushes of different hair elasticity and hair volume produce words of different forms, and hence express differently. Similarly, knowledge of choosing an appropriate piece of paper is crucial in the making of a masterpiece.
Different paper has different rate of absorbing the ink.
This difference in the rate of absorption again changes the forms of the words. Together with the basic knowledge of tools, the knowledge of executing the basic strokes is essential too. The imagined motion entails the speed, strength, linearity, and curvature and body motions. This inner motion would then stimulate a physical motion that will execute the writings. With perfection in the execution, all the intended qualities and characters of the words are accurately displayed.