I've used it twice, but not outdoors, so I don't think there are any noticeable major stains. The smell of the material still lingers. Although I haven't used it much, there may be some minor dirt, so please purchase it if you understand this. ------------------------------ [CHUULII] Insulated Cooler Bag, Large Capacity, Summer/Winter, Cooler Box, Self-Supporting, Eco Bag, Camping/Leisure, Picnic, Sports Day, Cherry Blossom Viewing, Shopping Material: Polyester, PEVA Handle Material: Cotton Manufacturer: CHUULII Capacity: 30ℓ ASIN: B0DDKCL7R9 Color: Gray Size: Approximately 52 x 20 x 43(h)cm Made in China [Design that enhances cooling & insulation functions] Solid thickness and high functionality. 3-layer insulation (outer fabric is Oxford, middle fabric is thick pearl cotton, and lining is high-quality PEVA) prevents heat from entering the bag, allowing for long-lasting low temperatures. The inner fabric is designed to prevent leaks even if ice melts inside. (The inside is made of waterproof vinyl, so you can easily clean it by wiping it off if it gets dirty) Note: To maintain low temperatures for a long time, use the necessary amount of ice packs.