What cartridge do I need for spray painting versus sanding?

Reviewers and the listings themselves distinguish particulate filters (N95/P95/P100) for dust and sanding from organic-vapor (OV) cartridges for paint, solvent, and chemical fumes. For spray painting, community and retailer reviewers point to combination OV/P95 or OV/P100 cartridges; for sanding and woodworking dust alone, a P100 or P95 particulate filter is the commonly cited choice.