I take certain equipment for granted in a kitchen and I don't really miss it until I am in a kitchen without it. The Silpat, a fiberglass and silicone mat for baking, is one such essential piece of equipment. I am guessing that Silpat stands for "silicone pour la pâtisserie," silicone for pastry. I have a bunch of them here at the restaurant and at home. Here you see an original Silpat that is about 20 years old and a newer knock-off Exopat from Matfer, a competitor.
So ubiquitous are these silicone mats that we call them Silpats no matter the manufacturer. I guess my Matfer rep is used to it: I call in an order for Silpats and she sighs and sends her Exopats. There is no functional difference between a Silpat and an Exopat, and little price difference. I prefer Silpats because I'd like to pay the company that invented the product. Still, my current kitchenware supplier buys from Matfer, so all my new mats are Exopats.
A French chemist named Guy Demarle invented the Silpat and his company Demarle still produces it along with other highly useful silicone products such as the groundbreaking Flexipans. Silpats come in a wide range of sizes, but the most common seems to be the half sheet pan size (11-5/8" x 16-1/2") with the cut corners that you see here.
They have a long lifespan if you treat them well. Wash them with soap and water and a soft cloth; don't put them in the dish machine. Even after you clean them, they're going to feel a bit oily to the touch. That's normal. Also, some staining is normal: see the stains on the Silpat above; what's a few stains after 20 years of hard use? Finally, store them flat to keep from breaking the fiberglass mesh. At home, I store mine in half sheet pans in a drawer that I built in directly under my ovens.
Silpats are a great replacement for parchment paper, which is really a euphemism for silicone paper. Parchment burns if exposed to a hot oven for very long; a Silpat will not. Once I bought my first Silpat about 20 years ago, my use of parchment paper for lining sheet trays became nearly nil (but you wouldn't want to cut a Silpat into a circle to line a tart pan, would you?)
We use them for all manner of pastry: cookies, tuiles, macaroons, biscuits, meringues, and so forth. And they also work great when used in pairs to keep items flat while baking. We often sandwich rounds of prosciutto between two Silpats and bake them until crispy. The crisp rounds then become part of a napoleon. Ditto for two ultrathin slices of potato sandwiching a sliver of truffle as a soup garnish. I recently made "bacon" from carrots in this manner. You just never know what you might need Silpats for and it makes sense to at least have two on hand.
Silpats are available at better kitchenware stores and on the net at Bridge Kitchenware and other retailers. Half sheet pan-sized Silpats are about $20. That's $20 really well spent.