Maximum Lightfastness Is Indicated As *** on Professional Art & Graphic Products
Faber-Castell indicates lightfast ratings on our professional art materials with a star icon. The lightfast rating indicates the items resistance to fading, which has been tested under museum conditions.
Star Ratings:
*** = Maximum lightfastness = 7 ,8 Blue Wool Scale
Maximum fade resistance (100 + years)
** = High lightfastness = 5, 6 Blue Wool Scale
Very good fade resistance
* = Reasonable lightfastness = 3, 4 Blue Wool Scale
Good fade resistance
Lightfast Ratings Determined by The Blue Wool Standard
Tested under museum conditions, Faber-Castell uses the Blue Wool standard to evaluate lightfastness. This standard utilizes eight scales to evaluate lightfast colors and it has been used for Artist paints for many years. 8 is the level of the highest lightfastness.
The Blue Wool test standard is comparable to ASTM D 5383-02 and ASTM D5383-97.
The Blue Wool standard relates to our star icons as follows:
*** = 7, 8 Blue Wool Scale
** = 5, 6 Blue Wool Scale
* = 3, 4 Blue Wool Scale
Prismacolor, Derwent and Van Gogh have embraced a new lightfastness standard developed in conjunction with The Color Pencil Society. This standard is called ASTM D 6901. This standard is not as precise as the Blue Wool method and only has two scales to evaluate lightfast colors.
It relates to our star icons as follows: I = *** II = ** and *
Why is the Resistance to Light So Important?
Drawings and art in general are meant to last for a long time. This can only be achieved when the art material that has been used resists light (e.g. sunlight).
The general definition of lightfastness is when a color remains visible and readable over a long period of time (it does not matter very much if the color changes).
Lightfastness Depends on Several Factors
Quality and quantity of the pigments
Quality of the pencil lead matrix (filler, waxes, emulsifiers…)
Quality of the paper being used:
When buying paper one should pay attention that it is...
Acid-free
pH-neutral
Resistant to aging
Preservation
A drawing should be protected from dirt, dust, changes in temperature and humidity. By keeping the drawing under glass for example.