Basicaly by common sense, considering a few factors such as:-
Try not to put it in an area of asthetic importance.
It should be in a location so that there are no undercuts as the mould opens.
It should be in a location that allows the part to stay on the moveing half as the mould opens, but still allows ejection from the moving half once the mould is opened
Regards
pat
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.