Precisely where to paint? (2,3,4)
I believe the answer is:
on the nail
'precisely' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for on the nail that I've seen before include "Where varnish is put" , "location of solution for digital protection" , "Exact" , "Where a coat may be hung" , "Where a hammer might go" .)