Roller refill timings

[Burlington]

Curious at what stage other rollerball users replace their refill ?

On my Caran d’Ache refills I find the ink begins to run dryer after approx 50% of the realistic maximum lifespan.

That said I’ve never used one until it physically runs dry and out of ink, just until I get sufficiently miffed at needing to go back over letters which left an indentation on the page but no ink behind.