You use the Stroke panel (Window > Stroke) to specify whether a line is solid or dashed, the dash sequence and other dash adjustments if it is dashed, the stroke weight, the stroke alignment, the miter limit, arrowheads, width profiles, and the styles of line joins and line caps.
You can apply stroke options to an entire object, or you can use Live Paint groups and apply different strokes to different edges within the object.
Layers Magazine instructor Dave Cross shows you how to apply fill and stroke in Illustrator and some handy shortcuts to work with fill and stroke in this video.
See also
Apply a stroke color, width, or alignment
- Click the Stroke box in the Tools panel, the Color panel,
or the Control panel. Doing so indicates that you want to apply
a stroke rather than a fill.
Stroke box - Select a color from the Color panel, or a swatch from
the Swatches panel or Control panel. Alternatively, double-click
the Stroke box to select a color using the Color Picker.
If you want to use the current color
in the Stroke box, you can simply drag the color from the Stroke
box onto the object. Dragging does not work on Live Paint groups. - If the object is a closed path (and not a Live Paint
group), choose an option from the Stroke panel to align the stroke
along the path:
Align
Stroke To Center 
Align
Stroke To Inside 
Align
Stroke To Outside
Note: If you try to align paths that use different stroke alignments, the paths may not exactly align. Make sure the path alignment settings are the same if you need the edges to match up exactly when aligned.
Create dotted or dashed lines
You can create a dotted or dashed line by editing an object’s stroke attributes.
- Click the icon: Align Dashes to Corners and Path Ends,
Adjusting Length to Fit
. This
option allows you to make the dashes at the corners and ends of
the paths consistent and predictable. If you need to retain the
appearance of the dashes without aligning then select the Preserve
exact dash and gap lengths 
icon. 
Dash Adjustments at the corners- A.
- Preserved exact dash and gap lengths
- B.
- Aligned dashes to corners and path ends, adjusting lengths to fit
- Select a cap option to change the ends of the dashes.
The Butt Cap
option creates
square-ended dashes; the Round Cap 
option
creates rounded dashes or dots; the Projecting Cap 
option
extends the ends of dashes. 
6-point dashed lines with dash gaps of 2, 12, 16, 12- A.
- Butt cap
- B.
- Round cap
- C.
- Projecting cap
For a video on creating perfectly dashed strokes, see www.adobe.com/go/lrvid5213_ai_en.
Change the caps or joins of a line
A cap is the end of an open line; a join is where a straight line changes direction (turns a corner). You can change the caps and joins of a line by changing the object’s stroke attributes.
- In the Stroke panel, select a cap option and a join option.
If the options aren’t showing, choose Show Options from the panel menu.
- Butt Cap
- Creates stroked lines with squared ends.
- Round Cap
- Creates stroked lines with semicircular ends.
- Projecting Cap
- Creates stroked lines with squared ends that extend half the line width beyond the end of the line. This option makes the weight of the line extend equally in all directions around the line.
- Miter Join
- Creates stroked lines with pointed corners. Enter a miter limit between 1 and 500. The miter limit controls when the program switches from a mitered (pointed) join to a beveled (squared-off) join. The default miter limit is 10, which means that when the length of the point reaches ten times the stroke weight, the program switches from a miter join to a bevel join. A miter limit of 1 results in a bevel join.
- Round Join
- Creates stroked lines with rounded corners.
- Bevel Join
- Creates stroked lines with squared corners.
- Butt Cap
Add arrowheads
In Illustrator CS5, you can access arrowheads from the Stroke panel and associate controls to adjust size. Default arrowheads are available from the Arrowheads drop-down list in the Stroke panel. Using the Stroke panel, you can also easily swap arrowheads.
You can resize the tip and end of the arrowheads in
dependently, using Scale option. If you want to link the start and end of the arrowheads scale, click the Link Start and End of Arrowheads Scales icon, adjacent to the Scale option.
You can also adjust the path to align to the tip or the end of the arrowhead, using the Align options. The options are:
Extend arrow tip beyond end of path
Place arrow tip at the end of path
Note: To remove arrowheads from objects, choose the None arrowhead option from the drop-down list.
Customize arrowheads
To define custom arrowheads, open the Arrowheads.ai file, which is located under ShowPackageContent\Required\Resources\<locale>\ (for Mac) and \Support Files\Required\Resources\<locale>\ (for Windows). Follow the instructions in the file to create custom arrowheads.
Place the updated Arrowheads.ai file at: <Illustrator home>\Plug-ins\ and avoid replacing the existing Arrowheads.ai file.
