Now, in a recent study, researchers from Japan found a simple and low-cost way of tuning the reflectance spectra of pencil ...

Pieces of pencil lead on the floor marked up the new carpeting. Only one teacher enforced the new rule, Nora said, pretty much erasing the ban. Nora’s 17-year-old brother Leo Rodriguez said he ...

The pencil “lead” is actually a mixture of graphite and clay. More clay in the mixture makes the lead harder. A harder lead has a higher number. Pencils are numbered from 1-3 but most people use a ...