Avoid detailed cleaning of fossils in the field. Paul uses foil as a separator to protect the rest of the theropod skeleton before adding layers of plaster-soaked burlap. Before applying a plaster and burlap shell, or jacket, a protective layer is needed over the bone so that the plaster will not stick to it. The experienced digger will make sure that all bone surfaces are covered with foil or paper, and that small packets of fragments are put inside the jacket. In this way, the plaster will not stick to the bone, and any associated fragments will not become lost in transport.
Wet burlap absorbs plaster much better and makes a stronger jacket.
The experienced digger wets the burlap strips before submerging them in plaster, so that the strips absorb the plaster. Dry strips or strips that are not fully soaked will not unite with the plaster to make a strong jacket. Mixing the plaster into the water leads to a smoother mix. Plaster Plaster comes as a powder that becomes very hard when mixed with water. The experienced digger sprinkles plaster powder into a bin or bucket of water, so that the plaster is smooth.