A tissue graft comprising two or more layers of material wherein each layer comprises extracellular matrix (ECM) or polymeric material and wherein the layers are laminated together by interlocking portions of one layer with portions of another layer. In one embodiment, a tissue graft comprises a first layer of material having multiple lugs and a second layer of material having multiple holes, each lug of the first layer being located through a hole in the second layer, the holes and the lugs having dimensions so that the lugs engage with a surface of the second layer and interlock the first layer with the second layer. In further embodiments, a method of preparing a tissue graft by laminating and interlocking two or more layers, the use of a tissue graft for replacing or repairing tissue in a human or animal, and an apparatus comprising a mould, a lug cutting means, a piercing means and a means for pushing lugs through piercings in layers of a tissue graft.