Light fastness/ Wool (blue) scale - artificial irradiation by filtered xenon arc light

DIN EN ISO 4892-2; with filtered xenon arc lamp, sample area max. 240 x 400 mm²); with water sprinkling (water spray) or dry. It is also possible to determine the light fastness, e.g. of printing inks or dyed materials, according to the so-called wool scale (light fastness scale according to DIN ISO 12040 fastness level 1-8).

In short — AI-generated

This test evaluates the light fastness of printing inks and dyed materials on flexible packaging by exposing samples to filtered xenon arc light, which simulates natural daylight. Depending on the requirements, the exposure can be performed under dry conditions or with additional water spraying to simulate weathering effects.

The results are classified using the wool scale (levels 1 to 8), where a higher value indicates superior resistance to fading. This rating helps packaging developers and buyers ensure that designs and branding remain color-stable when exposed to light during storage or shelf life.

Text is AI-generated; based on test method data curated and verified by Innoform.

Test Method Group: Mechanical properties

Norms:

DIN EN ISO 4892-1 (2016-10) Plastics – Methods of exposure to laboratory light sources – Part 1: General guidance
DIN EN ISO 4892-2 (based on) (2013-06) Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-arc lamps
DIN ISO 12040 (based on) (1998-01) Graphic technology – Prints and printing inks – Assessment of light fastness using filtered xenon arc light
FINAT FTM 6 (2014-08) Resistance to ultraviolet light
DIN EN 20105-A02 (1994-10) Textiles - Tests for colour fastness - Part A02: Grey scale for assessing change in colour
DIN EN ISO 4892-3 (2014-02) Plastics – Methods of exposure to laboratory light sources – Part 3: Fluorescent UV lamps
DIN EN ISO 105-A05 (1997-07) Textiles — Tests for colour fastness — Part A05: Instrumental assessment of change In colour for determinatlon of grey scale rating
DIN EN 14932 (09-2025) Plastics- Thermoplastic stretch films for wrapping silage bales

Required Sample Amount: DIN A 4

Standard Tests

artificial wheatering, simulation of outdoor exposure

Specific Norm: DIN EN ISO 4892-2 (in Anlehnung)

In the case of outdoor wheatering the sample is exposed to the total range of global radiation of about 300- 3000 nm. The artificial wheathering is carried out by usage of filtered xenon arc light in the spectral range of about 300- 800 nm.

Create test order

artificial wheatering, indoor exposure behind window glass

Specific Norm: DIN EN ISO 4892-2 (in Anlehnung)

When the material is exposed to sunlight behind window glass (interior), the short wave spectral range below 320 nm, which is very relevant to the material aging, is filtered out. The artificial wheathering is carried out by usage of filtered xenon arc light in the spectral range of about 320- 800 nm.

Create test order

« Back to overview