A professional who tends machine that forms plain and window envelopes from paper rolls or precut blanks. Responsibilities include:

• Loads stack of blanks into rack of feed mechanism or positions roll of paper on machine rack, using hoist, and threads paper (web) through machine.
• Starts machine and observes progress of blanks and web through cutting, gluing, folding, and drying units.
• Pushes button to stop machine in case of malfunction.
• Fans handful of envelopes to inspect them for quality of folding, sealing, and glue application, and packs them in boxes.
• Counts pack of envelopes periodically to verify accuracy of mechanical counter.
• Pours glue into machine container to replenish supply.
• Wipes or washes glue from machine at end of shift.
• May adjust glue applicator and drying and pressing rolls.
• May be designated according to type of machine tended as plunger-machine operator; rotary-envelope-machine operator; side-seam-envelope-machine operator.
• May tend machine that forms envelopes used in cover of books (book pockets) and be designated book-pocket-machine operator.