While it might be tempting to use your stylish indoor furniture cushions on your balcony or patio furniture, this is generally a bad idea that will lead to disappointment and damaged goods. The primary reason is that indoor cushions are not designed to withstand the harsh elements of the outdoors. They lack the critical protective features of purpose-built outdoor cushions.
Exposure to sunlight will cause the fabrics of indoor cushions to fade rapidly. A sudden rain shower will soak through the material, leading to a host of problems: the internal stuffing will absorb water and become a breeding ground for mildew and mold, resulting in a musty smell that is nearly impossible to remove. Furthermore, the dampness can rust or warp your outdoor furniture frames. Even after drying, the cushion will likely lose its fluffy shape and become lumpy and uncomfortable.
Outdoor cushions are engineered with solutions for these problems. They are typically made from solution-dyed acrylic fabrics that are highly resistant to UV fading and are coated to be water-repellent. Their fills are often made from quick-drying foam or are even perforated to allow water to drain and air to circulate. For urban outdoor spaces, where furniture might be exposed to rain, sun, and city grime, investing in properly rated outdoor cushions is essential for longevity, cleanliness, and comfort. If you must use an indoor cushion temporarily, be absolutely sure to bring it inside immediately after use and never leave it exposed overnight.