Flat tops assume delicate tasks: They must retain the fibres so that the cylinder wire can fully develop its carding effect. In the process, they must absorb high forces, but at the same time be flexible in order to avoid fibre damage. Therefore, the hooks are embedded in a flexible ma­terial. This basis, the so-called foundation, offers a firm support for the hooks, but also sufficient flexibility. This flexibility allows a certain evasion of the hooks without permanent deformations. The hook must always return into its initial position.