The strictest etiquette calls for naming each person who is invited on the envelope.

So you'd have:

Mr. and Mrs. John Smith
John Smith, Jr.
Susan Smith
Sam Smith

The danger in using "Family" is that you might be thinking of "Family" as John and Mary Smith and their three kids, while the Smiths might think that "Family" means the two of them, their three kids and Great Aunt Sally, Uncle Clemans and their next door neighbor who is as close as family to them.

Anyone who isn't living at home with their parents really should get their own invitation.

Yes, camlan is correct. However, if there are teens still living at home (say 13 and up maybe), it is nice for them to get their own invitation if extras are within the budget-makes them feel pretty special.

Actually, the way I learned it was that the parents ONLY are on the outside envelope (Mr and Ms John J Jones) . Then the inside envelope has the parents (Mr and Ms Jones) and the first names of the children that are invited, in age order oldest to youngest.

Children over 18 still living at home should get their own invites.

I agree with les.

Agree with Les, and I would like to say I learned that the inside envelope should have the names as the Bride/Groom would address those people. So if it is their Aunt & Uncle, put Aunt Susie & Uncle Mike, Bobby, Jimmy, Sally.

If it is someone the bride/groom always called Mr./Mrs. then that should be on the inside envelope.

The inside envelope is just more personal.

les and bee sound spot on to me. When my bro sent his Committment invitations he addressed the outside to Mr. and Mrs. He did not mention anyone else, nothing on the inside. We knew this was a formal event, was told the facility does not tollerate children running around, he even stated to others that children were not appreciated. told our sis that only the people on the invitation were invited. Due to other issues I had with my bro we did not bring our children, yes his nephew and neice. Then he got all bent out of shape when we did not bring our kids. Just another reason I am glad they did not go.