Abstract
Many of the vibrantly coloured inorganic pigments prized for their colour fastness and thermal stability contain heavy metals such as cadmium and are being, or have been, phased out because of their environmental unacceptability. Some of the organic pigment replacements are renowned for causing dimensional instability in mouldings, particularly those manufactured from polyolefins. This study assesses the influence that pigments have on the in-plane shrinkage and warpage and out-of-plane distortion of a square plate moulding manufactured from high density polyethylene. Variables such as plate thickness and post-moulding treatment are considered, in addition to colour.