An investigation is carried out into the plane strain deformation of model laminates incorporating a single hard layer. A total of four laminates based on Al alloy(5053)-steels and Cu-W are investigated in which the relative hardness of the constituent layers, r(h), are in the range between 2 and 13. It is found that the deformation is uniform in the initial stages of plane-strain, the strain being partitioned equally between the constituent layers. The regime of uniform deformation is prolonged in samples with low r(h), and nonexistent in Cu-W (r(h) = 13). End of uniform deformation is marked first by necking and then the rupture of the hard layers into platelets leading to the so-called boudin structure. The deformation then becomes grossly inhomogeneous. The platelets deform less than the matrix and moreover volumes evolve in the matrix rhombic in shape in the immediate vicinity of the platelets into which deformation penetrates less. With continued deformation the platelets rupture further, whereby releasing parts of the constrained volumes. The relative hardness of the constituents layers are modified and the range initially as wide as 2 < r(h) < 1 3 narrows down with increasing strain and seems to move to a common value of around r(h) = 2.5.