Two considerable angles of the brush

Dear friends,

There are two major angles of the brush:

1. Position Angle

Position angle refers to the angle of the brush in relation to the painting surface, the paper. When one uses a brush to draw a line, the brush should be kept in a perpendicular position. As one tilts the brush, thus narrowing the position angle, a wider line is obtained, for there is more contact between the brush and the paper. In such tilted positions, the side of the brush is doing the painting. The lower the brush, the wider the line. If the brush is lowered to a 10 degree angle, one can get the use of almost the full side so that, if the brush is two inches long, the line will be nearly two inches wide.

2. Moving Angle

Only when the brush is in a tilted position (side brush) does the moving angle come into play. Let us consider a two-inch brush, which, of course, is two inches in length, and approximately a half-inch wide. Assuming a normal pressure, if held at a 45 degree position angle, about one inch of the side of the brush should be touching the paper.

But one can get a one-inch line only if the brush is moved at a 90 degree in relation to the direction of the line, hereafter to be called the "line of direction". For example, if the line of direction is directly north, the brush must move "cross-ways" in relation to the line of direction.

If the brush is held so that it parallels the line of direction (at a 12 o'clock position), the width of the stroke will be much smaller; it will be only as wide as the width of the brush, or about one-quarter inch. Here, the brush is moving a "straight way" in relation to the line of direction. In a straight way moving angle, by changing the position of the brush, i.e., raising its position angle, the line will become narrower. This is an especially useful technique in painting branches.

If the brush crosses the line of direction at a slant, say the "one o'clock" angle, then the line will be about three-quarters of an inch wide. If one were to make even the slightest change, say to a 65 degree position angle and a "two o'clock" moving angle, the resulting line would be noticeably different.

The principle is that the lower the position angle of the brush, the wider the line; the sharper the moving angle, the narrower the line.

In side brush, to get a desired stroke, there must be constant adjustment of the moving angle. The significance of this statement can be demonstrated visually.

For example, in drawing a branch, one wants to get a thinner line at the end of the branch to show its tapering. Also, one wants to show the changes in direction in the growth of the branch. The brush must cope with all these changes within the line. Thus, if one fails to adjust the moving angle of the brush in relation to the new direction of line, the result will be as in Figure 110a -- unwanted fat or thin strokes.

There is unwanted result because: the brush at first is straight way; when the direction is changed, there is no adjustment in the moving angle, so the brush is suddenly painting in a crossway movement, resulting in a thicker line than desired. With the change of direction, the brush is again straight way; no adjustment in the moving angle resulted an a thinner line than desired. Then the brush is again cross way, and straight way, giving unwanted lines.

Even though the necessary changes in the moving angles have been made; if the position angles remained constant, the lines are more or less the same width. Therefore, while correcting the moving angle, one must at the same time adjust the position angle.

Even with both moving and position angles corrected, the factor of pressure control is also essential. To show the tapering of the branch, one should start with a heavier pressure (to secure a wider line) and, then, gradually reduce the pressure to suggest the tapering end.

-- David Kwo