Barcol hardness

The hardness of rubbers, elastomers and softer plastics measured with a durometer that presses a spring-loaded indenter into the surface, most commonly on the Shore A scale for elastomers and Shore D for harder materials. Methods are standardised in ASTM D2240 and related ISO standards.

A pigmented, resin-rich surface coat applied to the mould face before laminating, which cures to form the smooth, weather-resistant outer surface of a GRP moulding. It protects the underlying laminate from moisture and UV exposure and provides the colour and gloss of the finished part.

A composite element built up from multiple bonded layers (plies) of reinforcement and matrix, consolidated and cured so that they act as a single structural material. Its stiffness and strength depend on the fibre orientations and stacking sequence of the plies.