Graph It Shake is the new alternative in opaque & permanent water based pigmented ink markers.
As the name suggests when using the pen you simply shake the pen to re-mix the pigments and then apply a pump action on the nib to allow ink to flow through.
When first used you will need to pump the nib a few times for the ink to flow through to the end of the tip. Once the nib is totally coloured with the ink you are ready to go. for all subsequent use simply shake before use and pump nib as required.