Before deciding on which invitations to get, the couple needs to set their wedding budget and figure out how much is allocated for invites. Having a custom designed card will make invitations unique but it will also cost much more. Many invitation ordering websites offer basic stock invitations with the only customization being the names of the couple and the location. The size of the invitation will depend on the type of envelope that is going to be used. If there are custom envelopes to go along with the invitation, then the size and shape does not matter. But if buying envelopes different from the style or size of the invitation, pay extra attention to make sure the envelope fits.