You can use the Corner Options command to quickly apply corner effects to any path. Available corner effects range from simple, rounded corners to fancy ornamentation.
A. Fancy corner effect with no stroke B. Same effect with 1‑point stroke C. Same effect with 4‑point stroke
For a video on using corner effects, see http://tv.adobe.com/go/4948/.
Apply corner shapes using the Corner Options dialog box
Use Live Corners
With Live Corners, you can apply corner effects to rectangular frames by clicking the yellow box that appears on the frame and dragging. In addition, you can apply a different corner effect and a different corner radius to each corner.
To remove corner effects, choose Object > Corner Options, and then choose None.
If you don’t want the yellow box to appear when you select a frame, choose View > Extras > Hide Live Corners.
Guidelines for applying corner shapes
If you’ve obtained plug‑in software that adds more effects, the Corner Options command in the Stroke panel can include additional shapes.
Corner effects appear on all of a path’s corner points, but never on smooth points. The effects change angles automatically when you move a path’s corner points.
If a corner effect significantly changes the path by, for example, creating a bulge inward or outward, it may affect how a frame interacts with its contents or with other parts of the layout. Increasing the size of a corner effect may push an existing text wrap or frame inset farther away from the frame.
You can’t edit a corner effect, but you can change its appearance by changing the corner radius or modifying the stroke.
If you applied corner effects but can’t see them, make sure that the path uses corner points and that a stroke color or gradient has been applied to it. Then increase the Size option in the Corner Options dialog box, or increase the stroke weight in the Stroke panel.