The procedure that you're trying to do is explained in the Knowledge Base for the WC 7425/7428/7435 here on Xerox.com.
Follow the above link and type, "print multiple paper types" into the search field, then press Search. The first search result will explain how to set up the job.
It took a helpdesk guy 2 hours over the net to set up a job using different trays. I guess I'm really asking if any of you out there do such a thing (print from diff trays on the same job, like printing a cover page from colored paper and the rest of the job in white), and do so easily. Needing to call a helpdesk and spend 2 hours setting up a print job is not my version of user-friendly.
We just leased a Xerox 7435 after having a Savin for 4 years. What we need to do is print our weekly bulletin (we're a church) using pre-printed bulletin paper for pages 1&2, and our announcements on yellow paper for pages 3&4, and have both folded into one "booklet" each week. This is our main need for a copier/printer, and so far our trainer can't figure out how to print different pages from different trays on the same job.
We did this every week for our bulletin and every month for our newsletter on our Savin, but so far we can't figure out how to "print pages 1&2 on tray one, and 3&4 on tray two."
Any ideas out there?