If you don't find a template in your search, you might compose a layout
within Word on 'custom sized' paper, such as 6x9 or 5x7 with the invitation
on the top and the RSVP on the bottom. Then you could fold the invitation and
use 'invitation envelopes'. Depending on the numbers of invitations, you
could 'slice' the RSVP off the 'custom sized' paper and insert bothitems in
the envelope. If you keep the RSVP to a postcard size. you could print your
return address on the back so the recipient would only have to put a stamp on
it for a reply.
