Protection against light and heat

○ Avoid prolonged exposure of the sofa to direct sunlight or heat sources such as radiators or stoves.
○ Keep a minimum distance of 50 cm from heat sources.
○ Intense, direct light, whether natural or artificial (e.g., from shop windows or nearby lamps), accelerates fabric discoloration, especially in dark colors.
○ It is recommended to rotate furniture periodically to balance wear and tear from exposure.

The strength of fabrics in light

What is fabric lightfastness?

Lightfastness is the ability of a fabric to retain its original color when exposed to prolonged sunlight or artificial light.

How is it measured?

In Europe, ISO 105-B02:2014 is the standard used to determine, by means of a numerical value, the resistance of a fabric to light. This test evaluates the degree of color fading when the material is exposed to light sources under controlled laboratory conditions.

The test simulates the effects of sunlight using fluorescent UV lamps or xenon arc lamps, allowing accelerated aging to be reproduced: approximately 100 hours of exposure is equivalent to 4 years of natural light.

During the test:

○ A fabric sample, with one part exposed and another protected, is placed next to a reference fabric based on the Blue Scale (wool samples with different known levels of fastness).
○ Both are simultaneously exposed to the light source under specific conditions.
○ The system rotates the sample around the light to ensure constant and uniform illumination.

At the end of the set time, a visual assessment of the degree of discoloration is made, comparing it with the standard scale: Grade 1: total loss of color · Grade 8: no appreciable loss.

Approximate values depending on fabric use:

○ Upholstery and interior decoration: between grades 3 and 5.
○ Upholstery for outdoor use or use in severe weather conditions: between grades 6/7 and 8.

As demonstrated by the fastness test, direct exposure to light, whether sunlight or intense artificial light, causes progressive color degradation in fabrics over time. This wear is cumulative and may appear unevenly on different parts of the same piece of furniture. For example, areas closest to windows or sources of intense light will fade sooner than areas that are less exposed.

It should be noted that all textiles, regardless of the quality of their dyes, are susceptible to photodegradation. In particular, natural fibers such as linen or cotton tend to undergo physical and chemical alterations under direct sunlight, which can lead to discoloration, yellowing, and loss of structural strength.

Factors influencing the lightfastness of a fabric

The strength of a fabric in light depends not only on the type of exposure, but also on key factors such as its composition and the type of dyes used:

1. Fabric composition: There are significant differences in strength depending on the type of fiber:

○ Mass-dyed acrylics, designed for outdoor use, offer extremely high resistance. In this case, the entire fiber is dyed at source, which means that even if the outer layer of the yarn degrades in the sun, the color remains uniform, as the inner part is also pigmented.
○ Synthetic fabrics derived from petroleum, such as polyesters, have good light resistance, although less than mass-dyed acrylics.
○ Natural fibers such as cotton, linen, and jute are less resistant to light, with linen being the most resistant in this category and jute the most sensitive.

2. Type of dyes used: The dyes used in the dyeing process directly influence color fastness. They can vary in their water solubility and lightfastness, and are mainly classified into three groups: direct dyes, disperse dyes, and reactive dyes.

3. Special treatments: To improve strength, some synthetic fabrics can undergo advanced processes such as Indanthren® treatment, developed by BASF. This method, although more expensive, provides significantly superior color fastness and durability, but is only applicable to synthetic fibers.