Download the Lightfastness Ratings for:
Summer (MFADISC01), Autumn (MFADISC02), Winter (MFADISC03) and Spring (MFADISC04)
Lightfastness refers to the properties of colourants, such as dyes or pigments, that describe how resistant to fading the colourant is when exposed to light. Lightfastness is particluarly important to consider when displaying artwork, or creating artwork that will be displayed in a bright environment.
When testing lightfastness, samples are exposed to light with wavelengths that correspond to the environment inside a house – which means that wavelengths of 320 nm and longer are used. At the same time, samples are exposed to higher temperatures (50 °C) so you can be sure that once you create your artwork with the permanent shades, you do not have to worry about it in hot summer days.
Conditions that are set for the testing of samples are exaggerated on purpose. They are more extreme than the conditions in an ideal environment, so that the stated consistency of the colours has a considerable safety margin. Therefore, if you cannot keep ideal conditions, you do not have to worry that your artwork will degrade quickly.
HOW LONG CAN OUR PRODUCT LAST?
Everything depends on the conditions where our products are used and on the conditions where the artwork is displayed. Generally we can say that the degradation of the artwork is speeded up by:
- Higher light load
- Thinner coatings
- Use of the wrong base (too acidic or alcalic materials, unsuitable additives in papers, etc.)
Under ‘ideal’ conditions, which should be met in every gallery that cares about the correct lighting of the artworks (so that the artworks receive a maximum energy load of no more than 300 kJ/m2 per year), our lightfastness scale can be interpreted as follows:
- 1* the colour layer will disappear within 25 years
- 2* the colour layer will change noticeably within 25 years
- 3* the colour layer will last longer than 25 years
- 4* the colour layer will last longer than 50 years
- 5* the colour layer will last longer than 100 years
TIPS TO EXTEND THE LIFE OF YOUR ARTWORK:
- If the artwork is not displayed you should store it in a dark and dry place with the usual temperature (15-25 °C).
- When the art work is displayed, ambient light should not include other wavelengths than those included in the visible light spectrum (UV and IR radiation does not affect the perception of the colours, but decreases the lightfastness). You can also use a protective glass that allows only visible light to come through.
- Choose a dry environment for the exhibition of the artwork and make sure that the source of light (which is usually the source of heat, too) is not too close to your artwork (as well as any other source of heat).
- Follow the suggested method of usage for the specific products (e.g. use of priming mediums, fixatives, etc.).
Artwork by Sarah Hankinson.
Content provided by KOH-I-NOOR Hardtmuth, a.s., 2019
Testing of the lightfastness in Koh-i-noor is based on the norm ČSN EN ISO 105-02 and is evaluated in accordance with the norm ČSN EN 20105-A02 (grey standard). We use the method 5 from the norm ČSN EN ISO 105-02, because the energy load is defined clearly and according to the standards in this norm
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