Seal script is extremely raw and of exceptionally archaic beauty. On the other hand, it is difficult to study due to its irregularity of forms and lines, as well as its complexity and, to an extent, its vague etymology. To be able to write seal script smoothly and without hesitation, one needs to study all other styles in depth.
It may appear easy to write, but in fact it isn’t. It requires a lot of skill and practice as well as superb brush control, applying the technique known in Japanese as enpitsu (円筆, lit. “rounded brush”) dependent on delivering a smooth and round line, achieved by “hiding” the sharp spear of the brush tip inside the line of a stroke, making it look rounded and smooth (藏鋒, zouhou - “hidden spear”).
Uniform stroke thickness and rounded edges are the basic rules of small seal and reisho (to a lesser extent) calligraphy scripts. The strokes should be consistent and preferably free of kasure (without white streaks within the line, caused by fast brush movement or deliberately excessive ink thickness). By rounding the line edges, the calligrapher loops the energy flow in a closed circuit and allows the spirit of his mind to live in the work forever.
Energy distribution, or energy flow, is one of the most important features of calligraphy. In Japanese it is called gyouki (行気, lit. “moving spirit”). It is defined by vigour, power, flexibility, knowledge, certainty and emotions. If one of these elements is missing, the characters look dead, pale, frozen and passionless.
The above, however, does not present the real challenge in writing a seal script, yet. The most difficult part is to make such a well-organized, neat and somewhat static character look original and alive, while preserving its “antiqueness” at the same time. It takes years and years to achieve mastery, and it comes naturally not only with practicing calligraphy, but also through training one’s mental strength. Visually harmonious and imaginative tensho does not represent the power and stability of your arm, but of our soul and mind. By “hiding the hair tip of the brush” we dismiss our pride and ego, and preserve within the lines inner harmony, that guides the soul.