ArcelorMittal Atlantique has developed the DWI UltraLow Aluminium grades to improve the rejection ratesduring the deep drawing of beverage cans. At the time ofindustrialization of this grade, an increase of slivers defectswas recorded. The analysis of these slivers permitted totrace down their origin to the continuous casting powder.The compared analysis of slags during casting, respectivelyon standard DWI and ULA DWI, pointed out infiltrationphenomena and inclusion pick-up. A high viscosity powderwas formulated. An acceptable sliver rate was achievedwith a strong decrease in downstream repaired coils.