Talk:mechanical pencil

Retractable and Extendable?
The terms "extendable" and "retractable" seem somewhat inadequate for describing the function of these devices.

"Extend" implies "make longer" or "make reach further", whereas for the pencil to be functional, it has to stay at approximately the same length. (Which it achieves by allowing the user to extrude more lead as the tip wears away.)

However "extrude" is normally applied to a malleable material such as dough or toothpaste, so I'm not sure it would be helpful as a substitute term here. "Propel" highlights this functionality, but its connection with "propellor pencil" may not be obvious to everyone. Does anyone have any better suggestions?

"Retractable" seems suboptimal for two reasons:


 * 1) The internal mechanisms does not act alone to pull the lead back in; rather you release the clutch and then push it back in, usually by gently pushing the whole pencil against a firm surface.
 * 2) Many people never retract the lead, and would not regard this as an important or defining characteristic.

When you release the clutch it does typically pull the lead back in slightly, but this is an incidental action, and cannot on its own retract the lead once it's extended.

Retracting the nib of a pen serves two important functions:
 * 1) it slows down its drying out, and
 * 2) it prevents accidental contact between the nib and surfaces that you do not wish to mark; in particular, it prevents diffusion of the ink into surrounding fabric, which would otherwise result in prominent staining.

In contrast, a pencil does not "dry out", and while there is still some risk of marking, its effect is far less without any diffusion.

We used to use the term "safety pen" to mean one that was leak-proof (because the nib was covered or retracted), but again that really seems pretty far-fetched for describing a pencil. Again, does anyone have any better suggestions?

Martin Kealey (talk) 06:06, 16 August 2021 (UTC)