The product is a 1/4" (6mm) flexible plaster board that can be bent/curved and is perfect for using as backdrops. To date the original section of the layouts backdrops have not one crack in any of the joins.
The trick to getting perfect joins that don't crack is to back block every one. The process is fairly straight forward and the only consideration needed is when requiring a hole to be made for trains to pass through you need to add a backing board (usually 1/8"-3mm) made of MDF.
This stops the plaster/drywall from splitting due to the force in the curved section.
Next stage is to mud up the joins with fibre glass tape, one thin coat then dry, followed by a single top coat and dry again with final sand. Then paint sealer and two coats of the final colour.