There are two common ways to fashion inside corners. One is to use a compound mitre saw to cut the ends of the corner pieces along two axes simultaneously. The other, called coping, is a two-step process, first to cut a simple mitre and then to use a coping saw to undercut the mitres.
The use of a coped joint for interior corners saves the trouble of having to determine and cut the exact inside degree measurement, since most corners are not exactly 90/45 degrees. Outside corners must be mitred, and care must be taken in measuring and cutting, since not all outside corners measure true. If the angle is not exactly 45/22.5 degrees, a corner measuring device or piece of scrap cornice may be used to obtain the right measurement before the final cut is made.
Hight Density / Low Density Cornics
XPS (Extruded Polystyrene) and EPS (Expanded polystyrene) are two types of polystyrene that is used to manufacture cornice from.
XPS has a smoother finish, and EPS has a slightly rougher appearance.
EPS is a cheaper option, however after the cornice is painted, the difference is hardly noticeable.
Designs
NCD has over a 1000 standard cornice profiles, but for the customer that needs something deferent our in-house design team will custom design something that suit your exact needs.