Once the scratch coat has been allowed time to set, the finish coat can be applied. While plastering on this top coating, the second layer of plaster will fill in the scratches on the underlying coat. This action essentially creates points all along the surface of the wall where the two layers are joined and are allowed to create a bond that provides greater stability to the finished plaster.
Within the last decade, acrylic has become very popular as an alternative finish coat to the traditional cement "stucco" finish. Both finish coats are excellent finish materials, can be integrally coloured and are vapor permeable, but this is where the similarities end.
Conventional cement finish has practically an unlimited variety of textures from smooth trowel, mission, and old English to combed.
Stucco, being cement based, can only hold so much pigment, and dark tones are not recommended. Stucco works best in light pastel shades, and some slight variation in color shade should be expected.
Both stucco and acrylic finish are relatively low maintenance and both can be painted when a change of color is desired. The life expectancy of a stucco finish coat has been proven to be several decades.
While stucco is a natural cement product, acrylic finish is a synthetic man-made coating.
Stucco cures to a hardened state while acrylics dry to their final hardened state. This is a critical difference when considering environmental conditions during application.
Acrylic finishes can come in just about any color imaginable and can be matched to almost any shade desired. The consistency of color is very good with acrylics, even in darker shades.