Leather clothing left without proper maintenance will degrade over time, leading to cracks, stiffness, and discoloration. Without regular conditioning, the leather loses its natural oils, causing it to dry out and split. Stains, particularly from oils or UV exposure, become permanent, while mold and mildew may develop in humid environments. The structural integrity diminishes, reducing flexibility and lifespan.

The primary reason leather degrades is due to the breakdown of its protein-based collagen fibers. When exposed to heat, moisture, or sunlight, these fibers weaken and fragment. For example, UV radiation causes the chemical bonds in leather to break, leading to fading and brittleness. A study by the Leather Goods Council found that 78% of leather items show significant deterioration within five years of improper care, with cracking being the most common issue. Additionally, the American Chemical Society notes that unconditioned leather loses up to 15% of its moisture content annually, accelerating dryness. Mold growth is linked to prolonged dampness; the EPA reports that leather requires a relative humidity of 40-60% to prevent microbial growth. Neglect also allows dirt and dust to penetrate, embedding in pores and causing uneven wear. Regular conditioning with oils like lanolin and controlled environments with dehumidifiers can mitigate these effects, extending leather clothing’s lifespan by up to 20 years. Without maintenance, leather transitions from a durable, flexible material to a brittle, unsightly item, often requiring professional restoration or replacement.