  Stripped-envelope stars can be observed as Wolf-Rayet (WR) stars, or as less
luminous hydrogen-poor stars with low mass loss rates and transparent winds.
Both types are potential progenitors of Type I core-collapse supernovae (SNe).
We use grids of core-collapse models obtained from helium stars at different
metallicities to study the effects of metallicity on the transients and
remnants these stars produce. We characterise the surface and core properties
of our core collapse models, and investigate their explodability employing
three criteria. In cases where explosions are predicted, we estimate the ejecta
mass, explosion energy, nickel mass and neutron star (NS) mass. Otherwise, we
predict the mass of the resulting black hole (BH). We construct a simplified
population model, and find that the properties SNe and compact objects depend
strongly on metallicity. Ejecta masses and explosion energies for Type Ic SNe
are best reproduced by models with Z=0.04 which exhibit strong winds during
core helium burning. This implies that either their mass loss rates are
underestimated, or that Type Ic SN progenitors experience mass loss through
other mechanisms before exploding. The distributions of ejecta masses,
explosion energies and nickel mass for Type Ib SNe are not well reproduced by
progenitor models with WR mass loss, but are better reproduced if we assume no
mass loss in progenitors with luminosities below the minimum WR star
luminosity. We find that Type Ic SNe become more common as metallicity
increases, and that the vast majority of progenitors of Type Ib SNe must be
transparent-wind stripped-envelope stars. We find several models with
pre-collapse CO-masses of up to $\sim 30 M_{\odot}$ may form $\sim 3 M_{\odot}$
BHs in fallback SNe. This may carry important consequences for our
understanding of SNe, binary BH and NS systems, X-ray binary systems and
gravitational wave transients.
