All our Timeless Rings in Platinum and Palladium are now "High Pressure Enhanced". By using a breakthrough high pressure process after casting, our Platinum and Palladium are up to 20% harder than regular platinum or palladium.
The result - rings that stay brighter longer and are more durable and longer lasting than other platinum or palladium rings.
More info and comparison at our HPE page - High Pressure Enhancement explained.