Sun fade and PLA color

Ultraviolet light breaks down the pigments in plastic, and PLA is no exception. A figurine in direct sun for a few hours a day will look measurably different after a year.

Which colors fade first

• Reds and oranges, which shift toward pink and then toward a dull salmon.
• Bright greens, which lose saturation and drift toward olive.
• Yellows, which go pale but rarely become ugly.
• Blacks and greys, which fade the least and the most gracefully.

How much light is too much

Indirect daylight is fine indefinitely. Direct sun through a window is the problem, and a piece in a south-facing window in summer gets the equivalent of a year of fading in about three months.

Fading is not damage. It is just a piece that spent a lot of time in the sun.

If a piece does fade, rotate it a quarter turn every few months so the fading is at least even. An evenly faded duck looks intentional; a half-faded one looks like a mistake.