  Distortion free negative group velocity pulse propagation is demonstrated in
a rare-earth-ion-doped-crystal (RE) through the creation of a carefully
designed spectral absorption structure in the inhomogeneous profile of Eu:YSO
and subsequently inverting it. The properties of the RE system make it
particularly well suited for this since it supports the creation of very sharp,
arbitrarily tailored spectral features, which can be coherently inverted by a
single pulse thanks to the long coherence time of the transition. All together
these properties allow for a large time advancement of pulses without causing
distortion. A pulse advancement of 10.9% with respect to the pulse
full-width-half-maximum was achieved corresponding to a time-bandwidth product
of 0.05. This to our knowledge is the largest time-bandwidth product achieved,
with negligible shape distortion and attenuation. Our results show that the
rare-earth platform is a powerful test bed for superluminal propagation in
particular and dispersion profile programming in general
