First, the center pen
Center stroke is the main operation mode of writing with brush. Cai Yong's "pen heart" refers to the pen tip and the pen tip. "Always painting" means always running in the middle of strokes. Because the brush is conical, the strokes in the middle are thicker and more inked than those on both sides, so the strokes written are round and full.
This is called "middle stroke". But sometimes, although the pen tip is in the middle of the strokes, the brush is not conical, but flat like an oil painting pen. At this time, the texture of the strokes written will appear flat and thin, so Cai Yong should put the word "round pen belongs to paper" on the front.
Second, the oblique pen
Eccentric stroke is different from central stroke. The tip of the stroke is not in the middle of the stroke, but on the side; That is, the pen tip is on one side of the stroke, the pen belly is on the other side of the stroke, and the pen tip and the pen belly walk side by side. The strokes on the front of the pen are smooth and even, and the ventral side of the pen is dry and uneven.
This kind of brush stroke with light on one side and hair on the other, because of its imperfection, has always been regarded as a sick pen by calligraphers. As for calligraphers' writing lines and cursive scripts, it is another matter that they are dry, wet and even occasionally deviated because of the acceleration of writing speed or in order to strengthen the rhythm of works.
Third, side attack.
Side stroke is a stroke between middle stroke and oblique stroke. That is to say, when the stroke direction (centerline) and the running direction (centerline) form an included angle of about 45 degrees from top to bottom, this stroke movement is called lateral stroke movement. The texture of the stroke lines written by the side pen is also between the middle pen and the oblique pen.
When the included angle between the stroke direction and the running direction is less than 45 degrees, the texture of the stroke is close to the central effect; When the included angle between the stroke direction and the running direction is greater than 45 degrees, the texture of the stroke is close to the oblique effect. Profile is widely used in calligraphy, but it is often used in Yan Zhenqing's regular script horizontal painting.