Supramolecular capsules composed of two or more self-complementary monomers held together by hydrogen bonds and other weak interactions such as cation–π and C–H–π interactions are able to encapsulate neutral as well as positively charged guests. This mini review will highlight work on transferring such non-covalently bound aggregates to the gas phase by soft ionisation methods, such as electrospray ionisation, and investigating structure and encapsulation properties under solvent-free conditions. These analyses reveal exact information about complex stoichiometry as well as about structure and stability of capsules composed of multiple building blocks. The review is organised such that each type of capsule introduced contributes a new aspect to the overall picture.