Pens are dust-free as is, the problem with a regular ballpoint or felt tip pen is that both inking mechanisms rely on gravity. When you’re in 0g the ballpoint won’t work at all and the felt will stop working after a point when there’s no gravity to pull more ink to the tip.
You could probably spin a felt until it rewets but you’d be liable to make a mess as well.
You’re just raising the question about why the pencils cost over $100 if all pencils are dust free. What was so special about them when the special pens were so cheap?
Pens are dust-free, pencils are not. Dust-free pencils are special and expensive because it’s a lot of chemistry and testing to ensure that. How do you cleanly sharpen a pencil for example? Special pens are special but cheap because the components to make them are still relatively simple, the ink is still standard. More expensive than standard pens by a fair bit but a lot cheaper and more practical than the pencils.
![[Partially incorrect, see comments.] Pens in Space](https://mander.xyz/pictrs/image/466a2af6-4d33-4f93-aa6c-eaaf49ab899f.jpeg){kind=link}
Pens are dust-free as is, the problem with a regular ballpoint or felt tip pen is that both inking mechanisms rely on gravity. When you’re in 0g the ballpoint won’t work at all and the felt will stop working after a point when there’s no gravity to pull more ink to the tip.
You could probably spin a felt until it rewets but you’d be liable to make a mess as well.
Don’t felt tip pens work by capillary action?
That do. The failure comes if the spacecraft use lower air pressure, then the ink is pushed out of the pen by the pressurised gas in the ink
The same thing causes some pens to leak in aeroplanes.
You’re just raising the question about why the pencils cost over $100 if all pencils are dust free. What was so special about them when the special pens were so cheap?
Pens are dust-free, pencils are not. Dust-free pencils are special and expensive because it’s a lot of chemistry and testing to ensure that. How do you cleanly sharpen a pencil for example? Special pens are special but cheap because the components to make them are still relatively simple, the ink is still standard. More expensive than standard pens by a fair bit but a lot cheaper and more practical than the pencils.
I misread you as saying pencils are dust free.