#835: Inkdicator

If you are using a ballpoint without a transparent barrel or which uses sealed refills, it’s possible to find yourself scribbling (or doodling) in a meeting and then suddenly run out of notetaking ability.

Today’s invention is to add a small blob of ink, in a contrasting colour to the reservoir in such pens. The ink is highly viscous and therefore largely immiscible. The life of such a pen is short and so serious colour bleeding by diffusion wouldn’t be a problem (at least in non-equatorial regions).

The user would notice that his or her blue ink e.g. had suddenly turned black (for say the final hour’s writing) and that it was therefore time to re-equip before the next lecture/meeting/oeuvre/opus.