White shirts yellow for two main reasons: body oils and sweat that oxidise over time, and detergent residue that builds up and dulls the fabric. Both are preventable with the right routine.
Treat collar and cuff grime before washing, avoid overloading the machine so detergent rinses fully, and never let antiperspirant build up — the aluminium reacts with sweat to create stubborn yellow stains.
For a flawless finish, professional steam pressing makes a white shirt look genuinely new. PRESSO uses brightening-safe processes and industrial steam presses to deliver a crisp, hotel-quality result.