The X-ray transmission of a number of radiographic components, some of conventional construction and some incorporating carbon fibre material, has been measured under clinically realistic conditions. At 80 kVp the use of carbon fibre materials enables the patient dose to be reduced by 30-50% depending on the existing equipment, type of examination and technique used. Typically the dose can be reduced by 3-15% by changing the table top, 6-12% by changing the front of the film cassette and 20-30% by using a grid with carbon fibre covers and fibre interspace. The higher cost of carbon fibre components can normally be justified by such dose savings. An indication of the absorption of all such components should be provided by manufacturers.