Ghosh (1968) did some commendable work on the flexural slip and other concentric folds under plane strain pure shear condition, in materials such as silicone putty and painter's putty and their mixtures in various proportions to alter the viscosities of individual layers. He also studied the development of folds experimentally under conditions of progressive homogeneous simple shear (plane strain) and found that the vergence of folds is opposed to the sense of shearing. He found that the relationship between fold elements and finite strain ellipsoid are chiefly dependent upon the orientation of the layered complex or that of individual layers within the complex with respect to the direction of shear.