The results of the WC analyses in the log    T_∗-log R_t-plane, which corresponds to the basic model parameters. The WC stars form a one-dimensional sequence with a slight offset for the WC9 stars. Stars appearing above the sequence turn out to be binaries. The symbol shapes indicate the different WC subtypes. The numbers next to the symbols are the WR numbers according to van der Hucht (2001). Binary systems analyzed as a pseudo fit have WR numbers in brackets. Stars with persistent dust emission are marked with a superscript “d”. The thin grey lines in the lower part indicate the thick wind regime where stars can be shifted along these lines without significant changes in the synthetic spectrum.