Melos "dark" type is used more in low temperatures (autumn or winter), for full-tone playing, in an orchestra, or for great solo concerts.

Melos rosins are tested to function effectively under any condition, for every single instrument.

You can mix different types of rosins to have the results he/she really wish. For example, a violin player can mix a violin MELOS 'light' or 'dark' rosin with a viola MELOS 'light' or 'dark' rosin.