Fifty replicas of the trunk surfaces were made by applying a gypsum method to female subjects (average are 19.3 years) in a normal posture. Each replica was developed and the flat trunk surface pattern was produced.
The gaps on the surface development pattern of the front trunk were regarded as a factor for unfolding the trunk surface onto a flat plane. There were the gaps of the FCL 1 (front center line 1), FWL (front waist line) and CWL (chest width line) in all front surface development patterns. But other gaps of the FCL 2 (front center line 2), FBL 2·3 (front bust line 2 and 3) and FASL 1·2 (front arm scye line 1 and 2) did not appear to all. The surface development pattern of the front trunk was divided into ten (1-10) blocks. By examining the shape of these blocks we were able to determine the equations of the relation among the lengths of the sides of the blocks. In blocks 1, 4 and 5, the lengths of the sides including the gaps of the FCL 1 and CWL were made by those equations. The gap of FWL was made according to the lengths of the sides of the blocks 1, 2 and 5.