Mechanical pencil
Mechanical pencils are frequently used because they are reliable, erasable, cheaply refilled and therefore a very sustainable product.
Fine lead pencils can be used for drafting, sketching and drawing or writing quick notes. Many illustrators are using mechanical pencils for drafting their art before finishing it with india ink.
In the wide assortment of mechanical pencils you also find propelling pencils which are as easy to write with as with normal mechanical pencils.