Base
If you activate one of these options, the corresponding values apply to all sculpting brushes (even if you call up a preset). Example: You set the size of the Wax brush to 15 and then switch to the Eraser, which also has a size of 15 if this option is activated.
If this option is deactivated, you can set separate values for all brushes.
You can also switch these options outside the brushes (see also 
Link Size)
If the option is deactivated, the brush size changes accordingly when the view is zoomed in/out, i.e. if the option is activated, the brush stroke always has the same diameter, regardless of how large the zoom is.
If this option is activated, you can also shape on polygon backs (the cursor will turn blue). However, the direction of brush action remains unchanged for most brushes (e.g. the Draw brush still moves object points in the direction of the surface normals). Exceptions here are Scape and Fill.
Here you can set how the brush preview should be displayed around the mouse pointer:
- Off: no preview is displayed.
- Screen: the preview is always displayed facing the camera.
- On Surface: the preview points in the direction of the average normals (of those below the brush diameter), making it easier to estimate the direction in which the shape will be formed (usually along the average normals).