I can’t imagine a day in the kitchen without parchment paper
Here’s more than you probably want to know about how parchment paper is made from Wikipedia:
Modern parchment paper is made by running sheets of paper pulp through a bath of sulfuric acid (a method similar to how tracing paper is made) or sometimes zinc chloride. This process partially dissolves or gelatinizes the paper, a process which is reversed by washing the chemicals off followed by drying. This treatment forms a sulfurized cross-linked material with high density, stability, and heat resistance, and low surface energy—thereby imparting good non-stick or release properties. The treated paper has an appearance similar to that of traditional parchment.
Mostly I use the parchment that comes in rolls, tearing off pieces to fit into and up the sides of rimmed sheet pans. Sometimes I use the rolled paper to line cookie sheets, but I also keep a box of the pre-cut paper on hand for such things as biscuits or cookies. I use a paper cutter to cut smaller pieces to set between layers of roasted vegetables, like tomatoes or peppers, to store in freezer containers, and I have even used squares of parchment to line muffin cups, where it does a much better job than those purchased paper liners.
I use it in the prep stage, to line pans that I’m carrying out to the grill, especially those carrying foods to be drizzled with olive oil, and to line pastry crusts for blind baking:
I use it for roasting vegetables and meats:
I use it like a funnel to pour foods, like after I’ve toasted the oats and coconut for my muesli:
And, of course, I use it for the typical things you would bake—cookies, muffins, biscuits—and even such things as breaded veggies and pastries, like empanadas: