Mix together the egg white and glucose. Gradually add the icing sugar until you have a stiff paste. Turn out onto a surface dusted with icing sugar and knead until smooth, wrap in clingfilm and leave it to rest for about 30 minutes or so before using. Roll and use as required.
Liquid glucose can be found in the baking supplies section of the supermarket. The cooking oil helps the pliability of the mixture and also adds to a nice sheen - simply rub over the finished cake with your hands, being careful to remove any rings first. This quantity should be sufficient to cover an 8" round cake.