I'm experimenting with slate roof tiles for a future build. Here we have a section of tiles. The tiles were created using dental plaster in a mold. The plaster was colored with a few drops of black paint while mixing, and some random gray/blue/brown paint was painted inside the mold prior to pouring the plaster. The tiles were placed as a roof section, then drybrushed.
The top 2 rows had no other painting, the bottom 2 rows had some lichens added with enamel paints. The right side has no textured lichens, while the left side has textured lichens added in a variety of colors and textures.
The painted lichens were toned down because they really stuck out. Lichens really stand out on the real thing, but it looked too bright in scale.
The textured lichens look a bit out of scale to my eye also, even though I like the areas around the tile joints.