Square cake tins are usually made of aluminum or tin, and measure 22cm x 22cm x 5cm. They come with or without a non-stick coating. Square cake tins are ideal for brownies, slices, and bars, but not recommended for cakes since the centre of the cake forms a tall mound and the top looks humpy and uneven. Pieces of cake cut from the sides are typically thinner than those nearest the centre, which are thicker and higher. Even with a non-stick coating square cake tins should be greased and then lined with wax or baking paper.