Did you know historically the outer envelopes were used as a means to protect hand delivered invitations from the elements? Many moons ago, the mail system wasn't quite as what it is today, and mail was often damaged en route to it's destination.
Invitations, for example for weddings were sent in double envelopes to protect them. Once delivered to the recipient, the outer envelope marred from the travel was removed and then discarded, while the inner envelope holding the invitation remained pristine. To prevent damage to the invitation, the use of double envelopes became the norm. However, today it's more of a personal choice to use this method when mailing your wedding invitations.
On the outer envelope's front, is where you put the destination address. On the back flap of the envelope is where your or the sender's address should be placed. This is important to prevent loss, in case the invitation needed to be retuned for whatever reason.
Tip: When mailing your wedding invitations, especially if they are unusual in shape and size, boxed, or are embellished, ask your postmaster to hand-cancel (meaning they won't go through the postage machine) your envelopes. This service is time sensitive, and may cost additional to the stamps on your envelopes. So that you can prepare, call or stop by your post office and see how requests like this are handled. Bottom line? This will give you peace of mind that your guests will receive your invitations in good condition.
Happy Invitation Planning!
Until next time,