Below is the list of the painting tools available in Substance Painter :
The paint tool allows to apply Brush Strokes with a specific material over the mesh in the project.
The eraser allows to remove any existing paint information.
The Projection allows to apply a material or texture aligned to the current point of view.
The Polygon Fill allows to select polygons on the 3D mesh to create masks base don the geometry.
The Smudge tool allows to stretch, mix and blur color but also other material properties.
The Clone tool allows to duplicate or patch any part of the existing material on the 3D mesh.
The Material Picker allows to pick on the surface of the 3D mesh the material properties (color but also other channels).
The Quick Mask allows to create a temporary mask that can be used to create areas that won't be affected by other tools.