Select the cropping tool and click in the picture block containing the gradient.

Choose Gradient from the Graphic menu and click Screen.

Deselect Use Document Default, and select Line Screen if you want to change the way the dots are organized. A dot screen prints as evenly distributed dots. A line screen creates the effects of parallel lines that create the picture, as in an engraving or on a television screen.

Type a different number of dots or lines per inch, and type a new angle.

Click OK to return to the Gradient dialog box, and click OK again.