Our most preferred master materials are Silicon (including SiO2, Si3N4) glass, quartz, fused silica, Ni (including compounds nickel–phosphorus), (stainless) steel. Polymer masters are also possible but are usually more susceptible to damage. Materials such as PMMA have been successfully used in the past as well. Rigid masters are preferred over film sheets for imprint layer thickness homogeneity reasons.
Ideal thickness is 0.5 mm to 10 mm with a non-textured area (preferably > 10 mm) around the texture. Thinner masters might compromise replication quality.