Provided is a method for preparing an assembly of integrated capsules, the method comprising the steps of: (i) providing a first body comprising a body reagent, wherein the body reagent is, or is contained within, a body medium (ii) contacting the first body with a bulk medium comprising a bulk reagent, and permitting a first capsule shell to form at the boundary between the body medium and the bulk medium, thereby providing a first capsule, wherein the shell comprises a product of a reaction involving the body reagent and the bulk reagent (iii) providing a second body comprising a body reagent, wherein the body reagent is, or is contained within, a body medium (iv) contacting the second body with a bulk medium comprising a bulk reagent, and permitting a second capsule shell to form at the boundary between the second body medium and the bulk medium, thereby providing a second capsule, wherein the shell comprises a product of a reaction involving the body reagent and the bulk reagent and (v) permitting the first and second capsule shells to integrate, thereby forming an assembly of first and second bodies. An assembly obtained or obtainable by the method is also provided.
