  This paper presents initial results from the ESA-funded ``SUPPPPRESS''
project, which aims to develop high-performance liquid-crystal coronagraphs for
direct imaging of Earth-like exoplanets in reflected light. The project focuses
on addressing the significant challenge of polarization leakage in vector
vortex coronagraphs (VVCs). We utilize newly manufactured multi-grating,
liquid-crystal VVCs, consisting of a two- or three-element stack of vortex and
grating patterns, to reduce this leakage to the $10^{-10}$ contrast level. We
detail the experimental setups, including calibration techniques with
polarization microscopes and Mueller matrix ellipsometers to enhance the
direct-write accuracy of the liquid-crystal patterns. The performance testing
of these coronagraph masks will be conducted on the THD2 high-contrast imaging
testbed in Paris.
