The phrase "plaster walls" refers to the walls made from a material called plaster, which is a mixture of water, sand, and usually lime or cement. Full definition
Does your partner plaster the walls with physical photos? (digitaltrends.com)
Not because it was trendy to have white plaster walls or subway tile, it's just always been a classic look for those homes. (theinspiredroom.net)
That is much easier said than done when you live inside a farmhouse with old plaster walls, but it the process was easy enough anyway. (lovegrowswild.com)