The results of a series of undrained triaxial tests on samples of kaolin with varying degrees of overconsolidation are plotted non-dimensionally and reveal a family of distinct contours of equal increment of strain. These contours apply whatever history of loading has previously been applied to the samples. The pattern of contours also applies to results of drained tests and it is shown how the complete test path of a conventional drained triaxial test on an overconsolidated sample may be estimated from the undrained test results. (a) for the covering abstract of the conference, see IRRD abstract no. 27995, and also 48401. /TRRL/