So one is interested to hire calligraphy expert. Or it might found printing of the envelopes for addressing by the way of computer, which is the most viable option as well. There are pros and cons in each and every option. The decision of invitation envelope addressing depends on the personal preference of person and that sort of tone he/she would like to set for the invitation to guests.
With use of the computer for envelope addressing is useful and inexpensive if one feel that they have bad 'Handwriting' or do not want to strain the hands from process of writing. It might be able to use some of nice font, which printed out, looks professional, beautiful and formal. It's also relatively simple to set up the envelope addressing of invitation cards on the computer. Some might choose to use labels by computer or print the addressing on the envelopes cards it self.
But with the use of computer there are so many disadvantages for address envelopesif some one chooses for printing the addresses on the envelope, there should some time require investing in printing, at a time as it would require feed in one envelope? Also, at the time of dealing with an envelope with liner, one may require to run a test to see if the envelope will successfully feed through the printer or not. There should some care required so one could not make an ink smear on the envelope at the time of removing the envelope from printer.
The major disadvantage associated by use of the computer is that as many as guests may find it as an impersonal touch of calligraphy, particularly by using labels, as they may think that they're part of a mass mail production. Generally, as long as the printing of computer is directly with the envelope addressing, many will find it as acceptable. However, there would always some guests who might have preferred the personal touch of a handwritten envelope addressing invitation card.
The advantages of envelope by hand writing are that it's inexpensive, and with the help of family & friends, relatively quick to accomplish the task. It also gives a personal touch in the wedding ceremony. The guests would be pleased that one has spent the time for writing an envelope addressing for them. But some of disadvantage for hand writing envelope addressing is that the particularly writing may not be legible. Meanwhile, if the address couldn't be read by the post office staff, it would cause delays in some of the invitations being sent to guests. In addition, the handwriting may not look as simple and formal as one wish. If friends help in writing envelope addressing, accidentally they may misspell address or names because of not familiar with the family.
For more information: Calligraphy styles of Envelope Addressing
Jimmy John Calligraphy Experts - Sample Reception Card