In pastry-making, lining a mold means lining the sides with a layer of material (butter, flour, sugar, papier cuisson, cookie, jelly, caramel, etc.) to prevent the preparation from sticking during baking. This technique facilitates unmolding by preventing the dough or preparation from sticking to the sides of the mold.
Example: "Chemiser the tin with baking paper before pouring in the batter."
Meaning: Line the bottom and sides of a baking tin with strips of baking paper, then pour in the pastry.
Remarks: The mould and its paper are often buttered or greased before the batter is poured in.