Pour 1 cup of bleached all-purpose flour into a bowl. Add in 1/2 cup of table salt and mix well with a spoon.
Pour in 3 tbsp. of white acrylic paint and 1 cup of water. Mix with a spoon for 3 minutes until the substances are combined into a thin paste.
Place the diorama onto a sheet of newspaper so that the stucco does not damage furniture as you paint it on.
Paint a thin layer of the stucco mixture onto the outside and inside of the diorama. Allow the layer to dry for 20 minutes. Repeat this process to make the stucco walls of the diorama as thick as you prefer.