In order to create a mask in QGIS that can focus the map readers' attention, I will be demonstrating the use of The shape digitalization tool, move feature using advanced digitalization, Inverted polygons style, Shapeburst style and finally Color ramps. I will demonstrate a series of solutions ranging from a simple borderline to a complex colourramp controlled shape burst styling 

Chapters 0:00 Focusing your map readers' attention 1:04 The tools used in this process 2:40 The setup 3:50 Creating the feature to define the hole(s) in the mask 5:20 The shape digitalization tool 6:03 move feature using advanced digitalization 6:23 Creating a simple delimitation symbol 7:02 Inverted polygons style 8:35 Shapeburst style 9:50 Shapeburst style with parameter 10:35 Map units Vs. Graphical units in style settings 12:24 QGIS Color ramps 12:54 Editing QGIS colour ramps 14:10 Adding new control points in QGIS colour ramps 15:33 Editing the QGIS colour ramp using the plot interface 16:40 Enjoying the result