If you do not see a separate line item for Painting or Finishing a line item, it's likely you'll need to utilize the scope 7 instead. 

The scope #7 is always going to add a line item for painting/finishing.

To apply this to an estimate, first find the item (i.e. Base Cabinetry) and then select the appropriate scope (Scope 7 - Paint/Finish). I've added a screenshot to help: