Depending on the constitutive relation, some components of the fields and stays continuous everywhere in a laminate while the other component are only piece-wise continuous.

Example

For example, consider conducting materials. The normal component of the current and the tangent component(s) of the electrical field are continuous, the remaining components are discontinuous.

- Generally, the vector field
is subject to some differential constraints (the vectors may be
divergencefree, curlfree, etc.) These constraints imply that some linear
combinations of its components are continuous on
the boundary between layers,

Here is a matrix projector on the subspace of continuous components.The components of are constant in the laminate and the the supplementary orthogonal components of jump on the boundary between layers.

Projections and are mutually orthogonal:

- The dual vector has the properties similar to the vector
, but its discontinuous components are supplementary to those of
the prime vector ; in other words, the continuous and
discontinuous components
of and switch their places:

The next Table shows discontinuous components of the fields in
the equations of interest.
These component are completely defined by the normal to the laminate.
The matrix projects vector onto as follows: