bghydro.com sells mylar by the sheet, but the 2 mil stuff isn't all that cheap. Pretty durable though. I would have used paint but getting paint to stick to laminate was kinda tough (as I learned from my two small cabinets), so I used mylar on the larger cabinet, and have no regrets.

It's not just a marketing gimmick; it really does help, as does flat white paint or anything with high reflectivity. Use whichever of the two, paint or mylar, that is easiest for you. If you're dealing with smooth laminate surfaces, mylar might be easier than paint. Sure was for me.