Artist Texture Paste
You apply texture past to your work surface prior to painting. It can be applied with a palette knife, moulded into anything you want. You then allow the texture paste to dry and begin painting over the top. Once dry it is possible to sand or carve to reshape. This is in the acrylic category but texture paste can be used with oil paint too. Please note that this is not design to be mixed with your paint, its design to create a surface prior to painting.