How many hours is the 8th grade of light-fast ink?
Apr 23, 2025
About 1000 hours or more
The 8th grade of light-fast ink usually corresponds to a light fastness of about 1000 hours or more, according to the following standards and test methods:
Light fastness grade standard
8th grade is the highest grade of light fastness, according to the national standard GB/T 250-2008 (Gray sample card for color fastness assessment of textiles) and the pigment light fastness test standard GB 1710-1979. Grade 1 is the worst and grade 8 is the best, which means that the color hardly fades under long-term light exposure.
Relationship between test method and duration
Artificial accelerated aging test: Through the xenon lamp test chamber to simulate light (refer to GB/T 22771-2008), the 8th grade light-fast ink needs to pass about 1000 hours of accelerated test, which is equivalent to several years of outdoor exposure.
Actual exposure test: Some manufacturers conduct long-term exposure tests in Hainan and other places. The actual performance of the 8th grade light-fast ink needs to be combined with specific environmental data.
Notes: The actual sun-fastness time is affected by the environment (UV intensity, temperature and humidity) and the printed substrate. It is recommended to evaluate it based on the specific product test report or accelerated test data provided by the manufacturer.
