A mortise is a rectangular cavity cut into the side of a shutter to accommodate a hinge. The hinge can be either a hanging hinge or an interpanel hinge on custom shutters.

The mortise for a hanging hinge reduces the gap between the window jamb and the shutter panel. The best type of mortise is deep enough for both leafs of the hinge, so the window jamb does not need to be mortised.

The alternatives to mortised hinges are surface mounted hinges and use of non-mortise hinges.

Flush mounted hinges are the lease desirable because they result in the larges gap along the edge of the shutter. This allows for a large amount of undesired light to enter the room.

Non-mortise hinges reduces the gap to that of a singe hinge leaf. One leave of the hinge fits inside the other.

In previous posts we have covered surface mounted interpanel hinges that attach to the front or back of the shutter panel. Needless to say, this type of installation is not recommended.