When for the first time in school they get a chance to write with a pen instead of a pencil, there is no limit to the happiness of children. Children buy different types of pens for themselves. However, the ink inside all pens is mostly of two colors, blue or black. Now the question arises that when so many colors are present in the world then why only blue or black color was chosen for writing. Let us know the science behind it. Blue and black colored ink The use…
Read More