Authors’ abstract: Let A be a complex commutative algebra with identity and let F be a closed subset of its spectrum X(A). There are several hulls associated with F, which are useful in the study of approximation, interpolation and separation problems: the polynomially and rationally convex hulls are the most popular, the A-convex hull has also been considered and there are also holomorphically convex hulls.
In this paper we introduce a family of hulls, denoted by \(R_ n(F)\), and we study some relations between these hulls and several known objects and invariants in commutative Banach algebras.