Always read and follow the care instructions and any warnings on the garment label. And, follow the General Rules for washable fabric stain removal.
Some fabrics which are white or pastel colored contain optical brighteners or fluorescent whitening agents (FWAs) which were applied during manufacturing. These agents can decompose when exposed to light and atmospheric conditions, or prolonged storage conditions. In some cases the entire fabric becomes dingy or develops a yellow cast. In other cases the yellowing develops only where exposed to light. The FWAs can also be damaged by the use of chlorine bleach.
Unfortunately, once the FWAs are damaged, the whitening agents can't be reapplied to the fabric.
All fabric bleach or the use of speciality products available in grocery or drug stores, such as Rit's "Whitener and Brightener" may help. Carefully read and follow the instructions on the product label, and check for colorfastness first.
MEN'S HORIZONTAL DR. COOL SHIRT
This shirt is constructed using Coolcore's patented chemical-free moisture and sweat activated material to make sweat work for you. Rather than a simple wicking technology, the material delivers three distinct functions: wicking, moisture circulation, and regulated evaporation to reduce the fabric's surface temperature by up to 30%. Unlike other workout shirts Dr. Cool is chemical-free so that cooling benefits last the life of the shirt. Learn more about this technology. Shop for this technology>
KATHMANDU ARCHON 65L BACKPACK v4
If you're new to multi-day hiking, or enjoy tackling the occasional Great Walk, the 65L Archon is the pack for you: sturdy and reliable, made from tough Cordura® fabric, it has everything you need (bottle pockets, pole and bed-roll attachments) and nothing you don't. The easily adjustable RS2 harness has a small to XL range built in to the harness design. The padded and stiffened hip-belt and shaped alloy frame-stays transfer the load where it needs to be, while the padded EVA shoulder straps, adjustable sternum straps and padded back panel makes the trek over the Tongariro Crossing more comfortable. Learn more about this technology. Shop for this technology.