This Pebeo Crackling Effect Modeling Paste Kit is an acrylic Medium that will create a crackle effect when applied to a surface. It is a two-step process & easy to use. The size & widths of the cracks will vary depending on the thickness that the Crackling Medium is applied. This medium is fully intermixable with acrylic colour & is ideal to be used in mixed media approaches to making artworks, as well as for those who are looking to experiment with creating new & exciting surface textures.