Many first time users worry that the porous surface of the EPS Cement Sandwich Wall Panel will lead to uneven paint finishes, but the right workflow will give you a perfectly smooth professional result. After the EPS Cement Sandwich Wall Panel installation is fully completed, use lightweight joint filler to fill all the panel joints and cover the screw or fastener positions completely. Paste a layer of high strength joint tape over the wet filler at every seam between two EPS Cement Sandwich Wall Panel pieces to prevent future cracking at the joint positions. Once all the filler is fully cured, use fine grit sandpaper to gently sand the entire surface of the EPS Cement Sandwich Wall Panel until it is completely flat and smooth. Roll on one full coat of high penetration wall primer to seal the porous cement surface of the EPS Cement Sandwich Wall Panel, before applying your top coat latex paint. This process will give you a paint finish that is as smooth and flawless as any traditional plastered concrete wall.