A lithographic printing plate substrate is conditioned for imaging in a printer engine by attaching a leader to the leading edge. The container comprises a container body which is open at one side with a peripherally extending container wall and a bottom, and a cover element. This allows simple and inexpensive paralleling of differently rated PSUs without complex load sharing circuitry. When the release is activated gravity operates to rotate the drawer cradle about the pivot. The magnet configuration in accordance with the invention has a very simple structure. Curable epoxy resin compositions comprising these Mannich bases are suitable owing to good obtainable surface properties in particular for coating, adhesively bonding and enhancing metallic and mineral substrates, as adhesive and sealant, and for producing mouldings and sheetlike structures.