What does the term "colorfastness" refer to in fabric testing?

The term "colorfastness" specifically relates to the ability of a fabric to resist fading or running of color when exposed to various conditions, such as washing, light, or atmospheric conditions. This definition highlights that colorfastness is primarily concerned with how well the dye or color applied to the fabric holds up over time and use without deteriorating or altering. Ensuring high colorfastness is essential for maintaining the appearance and integrity of fabric, especially in clothing and upholstery that may undergo frequent washing or exposure to sunlight.

The other options touch on different aspects of fabric quality but do not accurately capture what colorfastness means. For instance, the ability of fabric to retain its original shape pertains to dimensional stability rather than color stability. Resistance to staining describes how well fabric can withstand the absorption of substances that may discolor it, which is a separate property. Lastly, durability over time speaks to the fabric’s overall longevity and strength rather than its color retention specifically. Therefore, while these properties are important in the context of fabric testing, they are distinct from the concept of colorfastness.