You can set the following brush tip shape options in the Brushes palette:

Diameter

Controls the size of the brush. Enter a value in pixels or drag the slider.

Brush strokes with different diameter values

Use Sample Size

Resets the brush to its original diameter. This option is available only if the brush tip shape was created by sampling pixels in an image.

Flip X

Changes the direction of a brush tip on its x axis.

Flipping a brush tip on its x axis.

A.

Brush tip in its default position

B.

Flip X selected

C.

Flip X and Flip Y selected

Flip Y

Changes the direction of a brush tip on its y axis.

Flipping a brush tip on its y axis.

A.

Brush tip in its default position

B.

Flip Y selected

C.

Flip Y and Flip X selected

Angle

Specifies the angle by which an elliptical or sampled brush’s long axis is rotated from horizontal. Type a value in degrees, or drag the horizontal axis in the preview box.

Angled brushes create a chiseled stroke

Roundness

Specifies the ratio between the brush’s short and long axes. Enter a percentage value, or drag the points in the preview box. A value of 100% indicates a circular brush, a value of 0% indicates a linear brush, and intermediate values indicate elliptical brushes.

Adjusting roundness to compress a brush tip shape

Hardness

Controls the size of the brush’s hard center. Type a number, or use the slider to enter a value that is a percentage of the brush diameter. You can’t change the hardness of sampled brushes.

Brush strokes with different hardness values

Spacing

Controls the distance between the brush marks in a stroke. To change the spacing, type a number, or use the slider to enter a value that is a percentage of the brush diameter. When this option is deselected, the speed of the cursor determines the spacing.

Increasing the spacing makes the brush skip

While using a preset brush, press the [ key to decrease the brush width; press the ] key to increase the width. For hard round, soft round, and calligraphic brushes, press Shift+[  to decrease the brush hardness; press Shift+]  to increase the brush hardness.