Sandwich panel with openings

A sandwich panel, comprising:

• a first structural outer layer;
• a second structural outer layer orientated substantially parallel to the first structural outer layer;
• a core layer sandwiched between the first structural outer layer and the second structural outer layer;
• and
• a plurality of openings, at least some of the openings each extending through the core layer from a first edge of the core layer to a second edge of the core layer to provide an open-ended channel through the core layer, extending in a longitudinal direction of the openings, substantially parallel to the planes of the first and second structural outer layers, wherein the plurality of openings are surrounded on all of their lateral sides by the core layer;
• the sandwich panel having a length L in a direction substantially parallel to longitudinal direction of the openings, and a width W in a direction substantially perpendicular to the longitudinal direction of the openings, the width W being greater than the length L;
• and
• the openings being provided as voids in an otherwise substantially uniform body of the core material, and being substantially regularly spaced from one another in a direction perpendicular to the longitudinal direction of the openings.