Process for obtaining multilayer materials suitable for transformation into hollow bodies by drawing or drawing and ironing

In a process for obtaining a multilayer material suitable for transformation by drawing or drawing and ironing into a hollow body having a height to diameter ratio greater than 2.5, and comprising subjecting an aluminum alloy substrate having first and second surfaces to an anodizing or chemical conversion surface treatment for improving adherence thereto, covering one of the surfaces by adhering a plastic material film thereto, and covering the other of said surfaces with a coating of varnish of known thickness,

• the improvement comprising incorporating into said varnish a solid lubricant in the form of particles of known mean diameter which are harder than said varnish, the ratio of said mean diameter to said thickness being at least about 4, with said particles thereby forming protuberances in said coating of varnish.