Looking for an alternative to cotton? Flax is the oldest known fabric, and it’s comparable to cotton in all ways – some even better. Flax is eco-friendly and great for high moisture and humidity areas. Flax, otherwise known as linen, is less likely to mildew, keeps the body cool, and costs less than cotton. Another bonus – flax is less likely to fade in the sun. Wondering why some shirts say flax while others say linen? Flax sounds more eco friendly than linen – but have no fear, they are the same great fabric.