system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do some ball-pens dry out so fast but others can be uncovered for years and still work fine?
gpt
Because there are different types of inks put in to ball point pens. 

you have the standard issue Bic Crystal which uses a very dense and almost dry ink, it will go on forever uncapped without drying out, but in exchange it requires more force to write with. 

Then you have the gel ones which are softer to write with but at the expense of drying out a bit more. 

Then you have the liquid ink ones which will dry out easly but can use thinner tips and are much easier to write with. 

so depending on your taste, you can use a bic crystal which is cheap, rugged and hard to dry. 

Or something more refined like a Pilot G2 or a Uniball Signo which are a pleasure to write with but are more fragile and less resistant to drying out.  

If you´re a student and take care of your pens, for the health of your wrists and hands, i suggest you avoid BIC crystals.