The pen and marker allow you to create handwritten annotations and drawings or markups; or underline, strike out or emphasize text.

Using Pen/Marker

Choose Tool Pen to enable the pen. The pen writes on your document like a typical felt-tip pen.

To use the marker, select Tool Marker from the menu. The marker works like a typical highlighter - it does not obscure the text, and it is therefore well-suited for emphasizing certain portions.

Please note that all settings listed below are saved separately for the pen and the marker. Even though these settings are accessed in the same way on the menu or the toolbar, you will see that when you switch between pen and marker, the proper setting automatically takes effect.

Color, Pen Width and Tip

Under Tool Tool Styles , you can set the Color and Pen Width for both tools. You can select from the preset colors and widths, or define an exact color and specify the width in millimeters or inches.

You can also set the Tip Style for the marker tool. Choose from Vertical (default), Horizontal, Squared, Ball.

Pressure Sensitivity

When supported by your hardware, PDF Annotator can variate the pen width according to the pressure on the pen while drawing. You can enable this by selecting Tool Tool Styles Pressure-sensitive.


The Auto-Smooth function is especially useful for underlining, striking out, or emphasizing text manually. You enable this function by choosing Tool Tool Styles Auto-Smooth. If Auto-Smooth is active, PDF Annotator's intelligent logic recognizes an attempt to draw a straight line - even if not 100% successful, and turns this into a perfectly straight line. Auto-Smooth also automatically detects and corrects geometric forms like rectangles, circles or triangles.

The Auto-Smooth function can be applied separately to the pen and marker. This lets you, for example, always have it turned on for the marker in order to highlight an area, and to turn it on or off at will for the pen.
Auto-Smooth can also be activated temporarily by keeping the Shift key pressed while drawing.
When using the pen to write, if you notice that your writing is constantly transformed into straight lines, you have turned the Auto-Smooth function on.


With Auto-Snap, you can use the pen and marker tools just as you're used to, but it will automatically snap to text it finds in your document, and mark up only that text, in straight and exact lines. For the Pen tool, you can enable this feature by selecting Tool Tool Styles Auto-Snap: Underline (Line), Auto-Snap: Underline (Wave) and Auto-Snap: Strike Out. For the Marker tool, you can enable this feature by selecting Tool Tool Styles Auto-Snap: Highlight.

Make sure to disable the Auto-Snap options after using them, otherwise you won't be able to hand-write comments.

See also