With solid ink in a pencil form you can write and then sharpen the pencil or leave it dull for everything from fine point to heavy lines or medium lines. You can still use the eraser if the ink is eraseable. Ink pens go dry but the pencil with solid ink, depending on how solid, might last longer and you could tell when you're almost out of ink and get a new one in time to complete your writing tasks on time. Most schools and colleges require you to use ink, but they didn't specify which kind, only which color. We could make the solid ink pencils in all colors and use them for artistic purposes and other uses besides writing.