When you have decided where you want titles and backgrounds to begin and end you can cut the shots you intend to use as backgrounds into your cutting copy in the normal way, using the rush print. Then you can turn your attention to the edge numbers and give the laboratory instructions by quoting the numbers at which you want titles to cut in and out or fade in and out and where you wish the backgrounds to change as well.
You must ask the laboratories to prepare a dupe incorporating the titles and you must supply them with precise details of what you want, listed on an optical instruction sheet. Here are some details from a typical instruction sheet:
Start background dupe at 29U976– 4.
Start 20 frame fade in ...