Abstract: This invention relates to a composition of matter having a fibre structure incorporating a major proportion of heat shrinkable fibres, the structure includes within it discreet fibre groupings which serve to provide structural elements within the composition. The composition of the invention is capable of being formed to provide shaped products. A particular aspect of the invention relates to compositions comprising flame retardant fibres typically polyimide fibres which enables the production of flame retardent compositions. The density of the structures can be controlled as can the rigidity thereof.