An Underlay is used when laminating single sided items on a pressure sensitive laminator It consists of any grade of material, such as rolls of newsprint or used backing paper from Pressure sensitive adhesives, and is simply fed through the machine below the item being laminated to prevent adhesive from sticking to the rollers
provide with a base, support, lining, or backing; "underlay the boards with joists" put (something) under or beneath; "They underlaid athe shingles with roofing paper" raise or support (the level of printing) by inserting a piece of paper or cardboard under the type; "underlay the plate
A thickness of paper, pasteboard, or the like, placed under a cut, or stereotype plate, or under type, in the from, to bring it, or any part of it, to the proper height; also, something placed back of a part of the tympan, so as to secure the right impression