The first tool we have in Paint tools is "Subdivision". This allows you to subdivide the geometry, so that you can use the Paint tool in more detail. However, we recommend to avoid using the subdivision tool, as it adds extra geometry. 

With the Paint tool, we will do a vertex painting, so that when we add the Scatter (the points to generate the fractures) we can have more density of points in that area. In this way, we can configure our geometry to fracture it in a controlled way and choose where we want more density of fractures.