Solid Knee
Laminates arc around the inside of the knee from the base to the apex. On the outside of the knee they come to a definitive point where the ceiling meets the wall. This eliminates any gaps between the portal, wall and ceiling.

Open Knee
Again this style has the laminates running continuously around the knee to the apex. There is a gap behind the knee where the ceiling meets the wall. This allows the portal to curve away from the wall, curve around the knee in parallel form and rejoin smoothly onto the ceiling.

Reverse Knee
The continuous laminations are curved in two directions, creating an effect similar to a swan's neck. Being the most elegant curved knee designs it is frequently used in the construction of churches and halls.