The importance of fat thickness and size and shape of eye muscle in bacon pigs has initiated much work to establish convenient routine measurements that would most reliably estimate these qualities. Measurements taken of the muscle: fat ratios in the region of the loin have been found to be the best estimate of the whole carcass and (as discussed by Harrington, 1958) have been a valuable aid in carcass competitions, where, to ensure similarity between contests, judges have used standard photographs of cut sides. The use of routine photographic records of cut sides in nutrition and breeding work has not, however, been fully explored, but was used by American and German workers (Ferguson, Brennan and Buric, 1961; and Brohmann, 1961). The advantage of using photographic records is that the measurements can be made at the most convenient time and place and form a near permanent record. They can also be used in developing correlations with measurements on live pigs which might estimate the quality of the rashers later produced.