Shanghai North Optics offers the SP122 (Equal to EJ442) series plastic scintillators, which are used for α-ray detection, a ZnS(Ag) layer is painted on the surface of Poly Methyl Methacrylate (PMMA) plastic materials, ZnS(Ag) are used as the scintillation materials, with a peak emission at 450nm. The usual thickness of ZnS(Ag) is 4.5mg/cm2  and the common thickness of PMMA is between 0.1mm to 10mm. SP122 plastic scintillators can be made into a large area, sizes up to 1000x1000mm are available. Advanced and sophisticated processing is used to make the ZnS(Ag) painting, which makes the final scintillators have excellent homogeneity and uniformity.