Adjusting grain direction and behavior
When you use a brush that interacts with paper grain, the results appear with each stroke. If you have a stylus and tablet, you can adjust paper grain by changing the stroke of the stylus on a pressure-sensitive tablet. In most cases, a light stroke colors only the peaks and ridges of the grain. A heavy stroke fills color deep into the pockets and valleys. You can also affect the brush interaction with paper grain by changing the brush grain settings.
If you want a uniform paper grain across an image, create your artwork first, and then apply the grain as a surface texture. If you apply paper texture before you create an image, the texture is erasable, and you cannot erase the paper texture without erasing brushstrokes at the same time. For this reason, it is usually best to add paper texture as a last step in developing your image.
By default, paper grain is fixed, which means that the texture is in the same position each time you apply a brushstroke. You can change this setting if you want grain to be applied randomly.
You can also change the look of brushstrokes by having the paper grain interact with stroke direction. This option works best when you paint with a stylus and use certain papers and brushes.
When you find a brush and paper combination that you really like, you can save it as a new look in the Look Libraries. For more information about saving looks, see Saving a brush look.
To randomize paper grain
The Random Grain Rotation check box is not available for all brushes.
To enable directional paper grain
property bar, click the 
.Factors such as stylus pressure, paper, and brush variant affect the appearance of brushstrokes when the Direction Toggle button 
is enabled. Papers with pronounced grain, such as Wood Grain and Gessoed Canvas, produce the best results.