A packaged mineral fibre insulating material has: a) a Recovered Thickness of at least 95% nominal thickness; and b) an Ordinary Parting Strength of at least 95 g/g; and c) a Weathered Parting Strength of at least 75 g/g the material comprising mineral fibres and an organic, formaldehyde free binder in a quantity of less than 15% by weight, preferably less than 10% by weight, said binder having been applied to the fibres of the insulating material in liquid form at pH of greater than 5.