Full Idea
A vague sentence is (roughly stated) true if and only if it is true for all ways of making it completely precise (the 'super-truth theory').
Gist of Idea
A vague sentence is only true for all ways of making it completely precise
Source
Kit Fine (Vagueness, Truth and Logic [1975], Intro)
Book Reference
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.119
A Reaction
Intuitively this sounds quite promising. Personally I think we should focus on the 'proposition' rather than the 'sentence' (where fifteen sentences might be needed before we can agree on the one proposition).