The specular value, plays a crucial role in how glossy surfaces are represented in renders.

Specular Value: Specular value, in essence, determines how much light a surface reflects. For surfaces like glossy high gloss laminates, acrylics, or materials with a reflective finish, the specular value tends to be higher. This is because these materials have a higher reflective surface, resulting in more light reflection. Acrylic surfaces, in particular, have an even higher specular value compared to high gloss laminates.

Customizing Specular Value: The ability to customize the specular value is a valuable tool in achieving the desired appearance of materials in your renders. When working with materials that exhibit a high degree of reflection, such as glossy surfaces, you may opt for a higher specular value, often ranging from 0.5 and above. This enhances the reflectivity and shine of the material, mimicking real-world high-gloss surfaces.

In contrast, when dealing with matte surfaces, where light reflection is minimal, you can decrease the specular value. Matte surfaces are best represented with values ranging from 0.1 to 0.2. This lower specular value contributes to a subdued and matte appearance.

Effect on Renders: The adjustment of the specular value significantly influences the visual outcome of renders. In your specific example, setting the sky blue glossy material with a specular value of 0.9 results in a more glossy and reflective appearance. On the other hand, when the sky blue matte material is set to a specular value of 0.2, it reflects less light, leading to a matte finish.

Effect of Roughness: Regardless of how high the assigned specular value is, assigning a roughness value of more than zero will significantly hamper the material's glossy effect. For the glossiness of the material to take full effect, ensure that the roughness is set to 0. If the roughness is set to a higher value, the only impact the specular value will have is a slight lightening of the material's base color (since it still helps reflect sunlight, albeit without the glossy effect.)

Below is a comparison of the combined effects of specular and roughness on the cabinet surfaces in three separate cases:

In conclusion, customizing the specular value allows you to fine-tune how materials interact with light in your designs. This level of control ensures that your renders accurately represent the intended materials, be it high-gloss and reflective or matte and subdued, ultimately enhancing the realism and aesthetics of your visual presentations.