You can manually select desired Material, Light and Render presets from other tabs.
2) Choose, Light and Render preset.
3) Choose Material preset. Fill you object with desired material via FillWithMaterial button.
4) Double your document resolution before using Document > Export for picture saving. For this you can use Double + AAHalf button from Document palette. For more information please hold CTRL button on Document > Export button for more information.
If you have some perfomance problems please use Standart Light and Render presets when sculpting.