SED of R Scl (log-log scales). Orange spectra: MATISSE data-sets in L- and N-bands with their associated error bars. Blue spectra: the ISO/SWS spectrum. Red points: photo metric fata from the literature. The solid black line is the best COMARCS+DUSTY model (see Sect. 3). Spectral features are labeled with arrows. ansets zoom onto the MATISSE spectrum (linear scales). SiC is marked as boldface as it is solid state, unlike the other gaseous species.