Nice rocks. What can I say? If you've every made rock molds, these are just the same as any other. Very easy to use, very detailed and perfect for cliffs, ledges and jagged outcrops. This is the 3rd I've used and they all come out perfectly, just make sure you mix properly and allow ample drying time of your plaster. Usually within 2-3 hours you can remove from them mold and leave to finish curing overnight before painting etc. If done right almost no flashing left to remove or little to no sanding.