Digital BW, The Print

I am needing to change from matt black to photo black ink cartridges 
on my R2400, in order to try printing some digital negatives.
My query is whether I can just swop them back when I need matt black 
again? Do I need to somehow seal up the matt black cartridge while it 
is out of the printer, or does it seal itself? I assume they must be 
interchangeable as required, and not to be ditched once removed.
Many thanks
John Fontana