At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance. At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance. At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance. At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance. At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance. At the core of precision technique is geometry, which, with a series of modernist principles applied to hair, creates cuts and colours of sheer simplicity. These geometric principles define what has become Sassoon’s ‘proprietary method’, where cut and colour integrate seamlessly in a harmony of shape and balance.