All the professional companies that are growing nowadays insist on professionalism. There are many reason for which customized stationary is used intensely. In that, there is also an A4 size letterhead. These letterheads are very useful in the business world. When the company has to send an official letter or certificate to its employee or to another company then it uses the letterheads. This gives an image of highly professionalism about a company to the other person.