How Fading is Measured

The most known among WPC researchers and engineers is the Hunter Lab color scale and a Hunter Lab Color scale meter. They were basically developed in the 1950s and 1960s, and the current formulas were finalized in the mid of 1960s. The most challenging question in that time and earlier was how to represent colors based solely on the numbers  

The Hunter Lab color space is organized in a rather simple way (Fig. 16.2). The L axis, as lightness, runs from top to bottom. The maximum for L is 100, the absolute 

Theory. The theory assumes that the human eye perceive color as pairs of opposites, namely, 

For most commercial WPG deck boards, the initial L value is between 40 and 55. For some, such as Trex Brasilia and Trex Madeira, it is around 32-35, and for Trex Winchester, Evergrain, and CorrectDeck, it is around 40. They are on a darker side of the color scale of composite deck boards, though for Trex Brasilia the color is mixed due to a dark surface exotic pattern. Among the most light-colored boards, with the initial L value close to or around 60, are Boardwalk, Fiberon Buff Cedar, Nexwood Red, Life Long, Procell, Millenium, TimberTech, and UltraDeck. 

When commercial composite deck boards fade, some their lightness goes up to 85 units and higher (see below). Typically, for most composite deckboards the L value goes from the initial 40-55 to 60-70 after only 1000 h in the weathering box. This will be explained later in this chapter. 

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