Assuming you’re using dyntopo (which is prone to bumps) I approach smoothing in 2 ways:
- Increase your detail size a bit (for larger polygon generation), like from 7px to 10px for example, and use the simplify brush to generate fresh topology over the problematic areas. Sometimes mesh wireframes generated by dyntopo can be “unsmoothable” and regenerating the topology will make it smoothable.
- If problematic bump artifacts persist I will use a low-strength scrape brush to flatten + smooth the bumps.
