Correct order to stuff invitations

After a few days of designing, printing, re-printing, translating, etc., we were finally finished with our DIY invitations. My fiance and I were about to stuff envelopes with our invitations and we just realized- what order do things go into the envelope? Isn't there some kind of etiquette for that? or correctness?

We had the actual invitation (a flat sheet), an information card, a RSVP card and an envelope to send back the RSVP.

First: Flat invitation

Second: Tissue paper (if you choose to use it)

Third: RSVP tucked under the RSVP envelope flap

Fourth: Information card/Map

If your invitation is folded, these items go in the same order and the stack is tucked inside the folded invitation.