how do flexible pencils work?

Question

Like this one. https://www.connectad.net/990701-thickbox_default/flexi.jpg

I’ve tried to look it up but it’s still mindblowing how they are able to manage this.

Thanks!

In: 6

Answer 1

Normal pencil core is made of graphite powder mixed with clay binder. The graphite is the black stuff that leaves marks, while the binder is what keeps the graphite from disintegrating. In flexible pencils they also add rubber, which makes the whole core flexible while still able to leave marks on paper because of the graphite.