Why I line the tin with baking paper, not just grease

The cake is already in the oven — and the tin base had only a smear of fat. Easy afterwards: the sponge sticks in a ring, the knife scrapes metal, the roll of paper never left the drawer. Before the batter I set a round of baking paper on the base and a narrow strip up the side: the batter does not grip the metal, the sponge comes out whole.

Why I line the tin with baking paper, not just grease. Greasing early is about a coat of fat; folding butter wrapper on the table is about a pack; putting the tray back on its shelf is about storage; tipping roasting fat into the pot is about stock. Here it is paper inside the tin before pouring — so the bake lifts without scraping.

If I forgot and the rim already seized — I ease a knife under, I line the next bake at once. I don’t flood the base with oil “just in case”. I’m not comparing rolls from the aisle — I use the one that already lies in our drawer.

I don’t need a sponge that stays half in the metal. I need a tin from which the bake leaves with the paper, quietly. In your kitchen before the batter do you line the tin — or only wipe fat “that will do”?