As the name says

The high pigment concentration in the Supracolor core remains intensely brilliant even when heavily diluted with water

The ink mixes cleanly between colors while wet

Whether you're using it for paint supplies

The 2B grade gives a dark

pilot frixion refill patron 1 0 mm 3 pack FD As the name saysThis Pilot FriXion Ball gel ink refill in 1. 0 mm fits the medium tip size used across the FriXion Ball, FriXion Clicker, and FriXion Pro pen range, with three gel ink cartridges of the same color in each pack. As with the rest of the FriXion line, the ink is thermo sensitive: the friction tip on the pen generates heat, around 60C, that turns the ink transparent on contact, letting you erase and rewrite over the same spot without damaging the paper