Information about the lightfastness test

How long does the test take?
The machine used to carry out the test for fade resistant markers has two Xenon lamps, both consisting of 2200 watts each. The duration and intervals are specific to different kinds of ink.

How are the test results rated?
The text will yield the results ++, +, o, -, - - depending on the marker’s lightfastness. A result of ++ means that the fade resistant marker is of high quality. Any products that achieve the ++ or + rating will be labelled as so by edding.

The method used to test lightfastness
An exposure unit is used to conduct tests for fade resistant markers. With this machine, it’s possible to set the following parameters:
- Irradiance
- Temperature
- Relative humidity
The machine has several standards already programmed so the correct one (in this case ISO 105-B02) needs to be selected prior to commencing the lightfastness test.
The Blue Wool Scale, which ranges from 1 to 8, is mandatory and used to measure lightfastness, in accordance with ISO 105-B02. A 1 on the scale is low and 8 is very high, therefore, the higher the number, the higher the light resistance. The duration of how long a mark is lightfast also depends on environmental conditions like summer or winter, which country and whether it is direct light or behind glass. The edding test center is always testing it within the same conditions for having a valid and repeatable result.
More interesting topics to read about

edding 750 paint marker
This fade resistant marker, designed to permanently label an array of different materials, even dark ones, is also waterproof and heat-resistant up to 400°C. The edding 750 paint marker is extremely lightfast and comes in 14 different colours, with more than half of them even remaining visible up to 1,000°C. The thin 2-4mm nib is perfect for fine writing, and thinner stroke widths are also available.

edding 500 permanent marker
Wear-resistant, waterproof, and lightfast: the edding 500 permanent marker can be used for labelling plastic, wood, metal, glass, and cardboard. Its compact size means it can fit into the fullest of toolboxes. The 2-7mm nib allows for thick strokes so products can be clearly marked. These markers come in ten bright colours and are also refillable.