For many years I also had to take larger items (like 2-page magazine ads or dealer tabloids) scan them in sections and then stitch them together and resize the finished product for catalog and other uses in 8 1/2 x 11 size. Unfortunately, one of the last Windows 7 updates changed enough critical code to make the Cannon-based soffware useless. Barbara and I have discussed taking various items to Office Depot or Fed Ex/Kinkos to have a master scanned on a larger scanner with finished product going on a flash drive and resizing for use off that. We can't do things like that very often as cost adds up quickly.
Once again, Jim Betts has come to the rescue by using his abilities and resources. I only wish "stitch" came back so I could do these kinds of things and even help Jim out.
