The Ising chain realises the fundamental paradigm of spin fractionalization, where locally flipping a spin creates two kinks (spinons) that can separate away at no energy cost, very different from conventional three-dimensional ordered magnets where a local spin deviation propagates coherently as a magnon. In a quasi-1D system the mean-field effects of the weak 3D couplings confine the spinons into a rich structure of bound states, analogous to quark confinement into mesons. Here we propose to tune externally the confinement potential between spinons by means on a variable magnetic field along the Ising direction to explore how the bound states in the quasi-1D Ising ferromagnet CoNb2O6 evolve from the limit of very weak confinement (many bound states, energy separation scaling as field to power 2/3) to very strong confinement (only two bound states, energies linear in field).