[tonwurm]

I did understand what you mean

but midi-volume is controller-data and has different behaviour than audio-volume, in PT you have to draw the curve

choose the pencil tool "Line" (or as said before with control pressed) and draw from the starting point to the end of your ddesired fade a straight line. The density of the controller data is selectable under preferences "Midi"

another way is to route your midi-instrument or VI to an aux-track and draw there your fades the same way as you do with audio-tracks