In the project settings you can set up rules to exclude some elements from your screenshots. This is very handy if you have some banners or highly dynamic elements on your site (slideshows, timers, weather widget, social networks widgets).
On the settings form you can write down selectors (each on single row) of the elements to be excluded.
One of most used is providing ID of the element. For example
for site http://www.tennis.com will remove the slider from the frontpage.
Next is you can exclude elements by their class. For example
will remove top, sidebar and bottom banners from the frontpage of http://www.tennis.com.
So after these exclusions screenshot will look like
There are also more advanced techniques. For example we can exclude elements by specifying rules like
-- means remove everything that has ID that starts with 'google_ads_iframe_'
-- means remove all elements that have class with ‘menu-mlid-’ inside the name.