1 INTRODUCTION

2 THE SURVEY AND DATA REDUCTION
2.1 The Ca H & K filter properties
2.2 Observations and coverage
2.3 Data reduction
2.4 Calibration
2.5 Global estimation of remaining systematic uncertainties

3 FROM CAHK MAGNITUDES TO A PHOTOMETRIC METALLICITY SCALE
3.1 Cleaning the contamination
3.2 Deriving photometric metallicities
3.3 Quality assessment of the Pristine metallicities
3.4 The photometric metallicity scale in different Galactic environments
3.5 Purity and completeness of finding low-metallicity stars

4 SCIENCE WITH PRISTINE
4.1 Searching for the most metal-poor stars
4.2 Characterizing the faint dwarf galaxies
4.3 Mapping the metal-poor Galactic halo

5 CONCLUSIONS