A generally hollow PET preform for making a stretch blow-moulded container, comprising: a threaded finish portion; a neck portion depending from said finish portion and including substantially cylindrical walls; wherein said substantially cylindrical walls of said neck portion have a thickness of 1.73 mm to 1.67 mm; a transition portion depending from said neck portion and including a first substantially conical wall section having a first taper of wall thickness; a main portion depending from said transition portion and including a second substantially conical wall section having a second taper of wall thickness, the second taper of wall thickness being lesser than said first taper of wall thickness; and a closed, generally rounded tip portion depending from said main portion, said tip portion having a third taper of wall thickness; wherein said tip portion includes walls that taper between a maximum wall thickness and a minimum wall thickness; the preform being characterized in that said third taper of wall thickness includes a percentage taper of between about 38% and about 45%, where the Percentage taper = [(maximum wall thickness - minimum wall thickness)/ (maximum wall thickness)] x 100%; wherein said maximum wall thickness is 4.1 mm to 3.9 mm; wherein said minimum wall thickness is 2.5 mm to 2.3 mm; wherein said preform is made of a poly (ethylene terephthalate) resin and has a mass of between 18.6 grams and 19.5 grams; wherein said preform comprises stretch ratios with respect to said container including an axial stretch ratio of 3.0 to 3.5, a hoop stretch ratio of 5.0 to 5.5, and a total stretch ratio of 16 to 18. a threaded finish portion; a neck portion depending from said finish portion and including substantially cylindrical walls; wherein said substantially cylindrical walls of said neck portion have a thickness of 1.73 mm to 1.67 mm; a transition portion depending from said neck portion and including a first substantially conical wall section having a first taper of wall thickness; a main portion depending from said transition portion and including a second substantially conical wall section having a second taper of wall thickness, the second taper of wall thickness being lesser than said first taper of wall thickness; and a closed, generally rounded tip portion depending from said main portion, said tip portion having a third taper of wall thickness; wherein said tip portion includes walls that taper between a maximum wall thickness and a minimum wall thickness; the preform being characterized in that said third taper of wall thickness includes a percentage taper of between about 38% and about 45%, where the Percentage taper = [(maximum wall thickness - minimum wall thickness)/ (maximum wall thickness)] x 100%; wherein said maximum wall thickness is 4.1 mm to 3.9 mm; wherein said minimum wall thickness is 2.5 mm to 2.3 mm; wherein said preform is made of a poly (ethylene terephthalate) resin and has a mass of between 18.6 grams and 19.5 grams; wherein said preform comprises stretch ratios with respect to said container including an axial stretch ratio of 3.0 to 3.5, a hoop stretch ratio of 5.0 to 5.5, and a total stretch ratio of 16 to 18.