In the 1890's the first serious devices to replace the pocket knife for pencil sharpening began to be widely available. They were hand held and many had inwardly pointing replaceable blades. While they were not as neat and compact as today's models, they would be recognizable to the modern eye.
The desire for a clean sharp pencil point is doubtless as old as the pencil itself, however the wood from which the pencil is made, and the lead it contains are sometimes forgotten as components needing to meet prerequisite standards of an acceptably high quality before the sharpener can be expected to perform its job satisfactorily.
A wood of reasonable quality and lead of consistent density and quality is important.There are 5 points which a sharpener has to have correctly configured for it to be able to perform its function successfully:
1. The sharpness of the blade
2. The angle of the blade
3. The angle at which the blade is presented to the wood
4. The angle of the taper of the sharpener cone
5. The rigidity of the whole structure
A high quality sharpener cannot compensate for poor quality wood and lead. High quality wood and lead will not withstand the damaging influence of a poor quality sharpener.
In order to ensure optimal sharpening, we recommend replacing the sharpener from time to time as the blade becomes blunt over time. This leads to breakage.