Including glass pencils, color changing pencils, charcoal pencils, drawing pencils, watercolor pencils, pastel pencils, etc., each has its own special purpose.
Glass pencils are used in industries, medicine, national defense, surveying and other sectors. They play a major role in writing or marking on surfaces such as glass, metal, enamel, ceramics, leather, plastic, and plexiglass.
Color changing pencils are commonly known as copy pencils. The handwriting cannot be erased with an eraser, which is suitable for writing important documents stored for a long time and recording accounts.
The drawing pencil is also called the tracing pencil. There will be a shading effect, used for direct printing after drawing.
Light-colored pens are harder, dark or bright colors are softer. This is all because of the content of the medium in the pen. Try a pink that is close to white! I can immediately notice that it is much harder than the bright pink pen.