The pectoral fins are simply laid flat to the side in making the cast.
Allow the cast to set hard before lifting it and removing the fish. Trim off the overlapping edge so that no undercut remains.
The cleaned and poisoned skin should lay in damp cloth over one night and is then laid in accurate place back in the cast. Pour it nearly full of medium thick plaster of paris, carefully mixed free of bubbles.
Settle a board, cut to approximate body outline but much smaller, into the unset plaster and press the flap edges of the skin back together over the board, molding edge of back and belly to round back away from trimmed edge of mold. This must be all done with accuracy before the plaster sets, but you will find it gives enough time. Do not work in a strung-up, nervous way.
When the plaster is set hard, remove fish from mold, hold it upon palm of left hand and tack edges of skin to back-board. (For general details of this method see [Fig. 21]).
Fig. 21.
Screw the specimen to a piece of board and adjust fins, carding them over little blocks and holding the cards with sharp toilet pins until drying is completed.