I've used small squares of Chef'splanet Nonstick Ovenliner and a hair straightener with great results. Thin, durable very-nonstick material heat stable to 500 F
Despite a brutal veg and early flower stage the long flowering sativas in the disposable-diaper greenhouse @ 35 degrees north are enjoying bright sun, highs in the mid 70's, and lows in the mid 50's for another week. Plus vibes to my friends in the PNW.