Needed: Multifunction Typewriter/Printer/Scanner

I want to print an address on a size of envelope that I don’t normally use, or a design on a custom-sized piece of paper.  I don’t want to fool around with a dozen test runs to make sure the thing is configured right.

What I want to do is to see the envelope or custom-sized paper onscreen, courtesy of the multifunction device’s automatic sheet- and envelope feeder.  While the paper is sitting there on the scanning glass, I want to type, correct, edit, and finalize the address or whatever it is that I plan to print.  I want to see my typing superimposed on the scanned image of the paper, exactly where and how it will print.

Then I want to press the Print button and let the machine feed the paper on from the scanning glass to the printing unit.  Of course, if I’m just doing sheet-feed scanning, I want the scanned documents to bypass the printing unit; and if I’m doing automatic sheet-feed printing, I want the blank sheets or envelopes to bypass the scanning glass.