Whenever it comes to picking out your wedding invitation envelopes it is important to keep a few things in mind.One of the most important things is to consider is what size that you want your wedding invitations to be. The standard wedding invitation size is either 4 x 6 or 5 x 7, with most people going for the 5 x 7 option. There are also many other proportions that are popular in wedding invitations. Some people like the square invitation, although this can cause problems because the postage it is generally more for square envelopes. Of course you also have to worry about whether you want to use inner and outer envelopes or if you just want to go with one envelope. This will depend upon the level of formality you want to portray with your wedding invitations. They also have a practical use in that the outer envelope protects the inner envelope from marks that it would receive in the mail. These are just a few things that you should consider when thinking about envelopes for your wedding invitations.