These are autoclaved fibercement sheets for interior or exterior facade claddings of the buildings with smooth surface look. There is no need of plastering after application.
The places where the sheets come together are filled with acrilic or polyurethane caulk, sanded and painted with any water based acrilic paint. Silicone paints should be preferred for exterior facade applications. Oil based paints can not be used on fibercement sheets.