Anyone with a bit of calligraphy knowledge knows that small seal script (小篆) is slender and elongated, while clerical script (隶书) is short and flat. But why is that?
Chinese characters are often called “square characters,” yet aside from Song typeface (宋体字), almost none of the traditional scripts are truly square. Small seal script is tall and narrow, while clerical script is distinctly flat and wide. This contrast is one of the most striking in the evolution of Chinese writing.
Qing Dynasty – Wu Rangzhi’s (吴让之)Seal Script Works
From the Qin dynasty to the Qing dynasty, seal script consistently appeared in a slender, elongated form—elegant and graceful in posture.
Clerical script, on the other hand, is characterized by its short verticals and long horizontals—solid, steady, and expansive in appearance.
Han Dynasty – Stele of Yi Ying - 汉代乙瑛碑
Han Dynasty – Stele of Ritual Vessels - 汉代礼器碑
Chinese writing evolved through the following stages:
Shell bone script → Bronze inscriptions → Big seal script → Small seal script → Clerical script → Standard script (kaishu)
Clerical script directly followed seal script, yet the two seem utterly different—like a son who bears no resemblance to his father. Historians call this transformation the “clerical transformation” (隶变) — a sudden, revolutionary change.
Why Did the Clerical Transformation Occur?
Few studies have addressed this question. Since 2012, I have researched the pictographic origins and evolution of Chinese characters, and I have gradually formed my own view. Here it is—not necessarily correct, but worth considering.
Before the invention of large-scale papermaking in the Han dynasty, writing materials were bamboo slips—narrow strips, typically about 8 millimeters wide. This extreme narrowness restricted horizontal strokes, forcing writers to elongate characters vertically. Some characters were even written upright. For example, in shell bone inscriptions:
From left to right: horse (马), elephant (象), dog (犬), dream (梦)
This vertical compression was dictated by the bamboo medium.
For nearly two thousand years, from the Shang dynasty to the Eastern Han, people wrote under this constraint. Characters could not expand horizontally, and lines of text had to flow vertically. (I’ve discussed why ancient people wrote vertically in another article, “Why Did the Ancients Write From Top to Bottom?”)
The Invention of Paper: A 2D Revolution
When large-scale papermaking emerged in the Eastern Han, everything changed.
I emphasize large-scale because, as modern scholars agree, Cai Lun didn’t invent papermaking from scratch—he improved existing small-scale folk methods. Acting on an imperial assignment, he surveyed local papermakers, collected techniques, and developed a process suitable for mass production. Paper became affordable, and bamboo slips quickly became obsolete.
Bamboo slips are one-dimensional—you can only write in one direction.
Paper, however, is two-dimensional—a flat surface where you can write in all directions, especially horizontally.
After two thousand years of constraint, people finally had space to let their brushstrokes stretch freely sideways. In this “psychological rebound,” writers deliberately extended their strokes horizontally. To achieve longer horizontals, they straightened the small seal script’s inward curves—transforming gentle arcs into bold horizontal lines or sweeping diagonals (nà).
For example:
The curved upper and lower arcs of the small seal-script “木” (wood) were straightened in clerical script—the upper arc became a flat line, the lower arc flared outward into a left-falling and right-falling stroke.
In fact, this tendency began as early as the Warring States period, when people were still writing on bamboo slips. Evidence from Qin bamboo texts excavated in Jingzhou (1993) already shows characters dominated by straight strokes—essentially proto-clerical script, though without the distinctive “silkworm head and swallow tail” flares yet.
By the Han dynasty, after paper became common, clerical script matured into its recognizable form, complete with those elegant flaring strokes.
The Birth of “Silkworm Head and Swallow Tail”
No ancient documents explain how these features originated. One theory suggests that someone—perhaps unintentionally—wrote this way, others found it beautiful, and the style caught on, becoming a hallmark of clerical script.
For example,
In the character “聿,” all curves of small seal script were straightened.
In “進,” the short lower line of the “止” radical was pulled diagonally outward into a long sweeping stroke.
The Desire for Long Horizontals
In the early 1970s, during construction of the Xiang–Qian (from Hunan to Guizhou) and Zhi–Liu (from Henan to Guangxi) railways, engineers from the Cheng–Kun Railway (from Chengdu to Kunming) came to my hometown, Zhijiang, a town at the edge of the Yungui Plateau. The roads there were wide and flat, so the drivers—accustomed to treacherous mountain roads—drove wildly fast. When people asked why, they said, “We were stifled too long on the narrow roads of the Cheng–Kun line—now we can finally drive freely!”
It was the same with writing.
After centuries of cramped bamboo slips, people finally had “wide roads” (paper) and expressed their joy by writing with long horizontals and sweeping strokes.
If a character lacked such long strokes, Han calligraphers would boldly redesign or even rotate it to create one.
For example，
The seal-script “heart” had no long horizontals. In clerical script, scribes reinterpreted its curves and stretched one diagonal into a long “silkworm-head and swallow-tail” stroke.
Another example,
The small seal-script and clerical-script forms look almost unrelated.
To understand, compare with earlier scripts:
- The shell bone script form (left) depicts a kneeling person with hands crossed over the chest.
- In big seal script (right), the body becomes a vertical curve, and the hands are represented by crossing horizontals in front.
Small seal script
- In small seal script, symmetry is emphasized—the left arm was extended downward to balance the right, making the figure look stylized.
Now, let see the clerical script, if we rotate the clerical-script “女”, left below, 90 degrees clockwise, we get the right one below, we can see the relationship:
The right vertical of clerical script corresponds to the right arc of small seal script, and the crossing strokes on the left match the crossed arms. By turning the form sideways, the Han scribes converted vertical lines into long horizontals, which is perfect for a Silkworm Head and Swallow Tail stroke —embodying their bold creativity.
This radical reworking was widely accepted—from court scribes to commoners—and became the standard.
The Spirit of the Han Dynasty
The Han people were open-minded and innovative. They achieved brilliance in many fields, including calligraphy—clerical script reached its peak during the Han dynasty.
That is why the descendants of the Central Plains proudly called themselves Han people - 汉族, their writing Han characters - 汉字, and their language Han speech - 汉语. The Han (and later the Tang) was truly among China’s greatest dynasties, giving later generations pride in being “Han.”
Decline of Innovation
We have just seen how clerical script revolutionized small seal script—a historical leap.
But modern Chinese people no longer possess that courage or boldness. We’ve grown conservative, afraid to deviate even slightly. As a result, after the emergence of regular script (kaishu), Chinese calligraphy ceased to evolve.
For language, that stability isn’t bad.
But for the art of calligraphy, it led to stagnation—a creative dead end.
A Personal Anecdote
Around 2012, when I was teaching Chinese at the Huaxia Chinese School in New Jersey, I once took part in a Peking opera performance organized by the Confucius Institute at Rutgers University.
I called the institute to ask whether they needed Chinese teachers. The program coordinator, an older lady, told me she preferred “standard Chinese” and opposed any deviation from standard forms. When I asked what she meant by “standard,” she said: “Song typeface.”
Later I emailed her samples of my work—studies on pictographic origins and pictographic calligraphy—but she never replied. Then I understood: in her eyes, I was a heretic for not using “standard” Song type.
To her, “standard Chinese” meant not only Song typeface, but simplified Song typeface. Ancient scripts like shell bone, bronze, or seal script were, to her, not “real Chinese.”
But who decides what “standard Chinese” is?
Is it the ancient ancestors who created the characters—or modern people who only recognize simplified forms?
As the proverb says, “A little knowledge is a dangerous thing.” That lady, with her half-bucket of knowledge, was nonetheless full of self-confidence.
If the ancients could return today and see simplified Song characters, would they still recognize them as “Chinese characters”?
Conclusion
The slender grace of small seal script and the flat boldness of clerical script both arose naturally from changes in writing materials—from narrow bamboo slips to wide paper sheets—and also from psychological liberation.
The clerical transformation was a rebellion against the constraints of the bamboo medium.
Over time, that rebellious spirit calmed, and with the advent of regular script, writing returned to balance—neither too tall nor too wide. Characters became truly square, regular, and standardized.
That made the language more consistent—but it also meant that calligraphy lost much of its distinctive vitality and artistic tension.
In short
The shapes of Chinese characters evolved not merely from artistic choice, but from the physical and psychological freedom of their writers—narrow slips bred slender forms, while broad paper invited sweeping horizontals.
Written in Feb. 1st, 2025
