Composite panels and sheets having insulating properties; carbon fibres, including in sheet form (not for textile use); carbon fibres for use in industry, including in sheet form; polymer fibres, including in sheet form (not for textile use); glass fibres; composite fibres of carbon and glass including in sheet form; composite panels having insulating properties; composite plastics materials for use in manufacture; carbon fibre reinforced synthetic resins, fabrics and sheets; plastics in sheet form; plastics containing carbon fibres for use in manufacture; sheets of plastic, composite materials, textiles of glass, plastic and carbon fibre; insulating materials, including those made from carbon fibre; sheets of fibre material, with the fibres being selected from carbon fibres, glass fibres, and carbon/glass composite fibres