Filters apply to an entire clip, shape, or image.
Add a filter:
Click the Audio Effects tab or the View Effects tab.
Drag a filter from the pane onto the timeline. When you drag the effect onto the timeline, Camtasia adds a yellow border around the locations available for applying the effect.
Click the Properties button 
to adjust the settings for the filter.
Reuse a filter:
If you customize an effect’s settings within the Properties pane and want to reuse the effect:
Control-click on a filter the timeline and select Copy Filters.
Control-click on the clip, shape, or image you want to paste the filter onto and select Paste Filters.
To paste onto multiple clips, shapes, or images, Shift-click to select the desired clips, shapes, or images. Select Edit > Paste Filters.
To remove a filter on the timeline:
Control-click on the clip, image, or shape.
A list of the filter(s) applied appear in the context menu. Select the Remove option for the desired filter.
To remove a filter on the timeline:
Click the Properties button .
Click the Delete button for the desired filter in the Properties pane.
Effects
About the Video Effects view
About the properties
Change the default duration