RAL Color and Gloss Guide

The two concepts most often confused in the field are RAL and gloss. The customer says “RAL 7016 anthracite,” the color from the gun matches, but the part comes back: “this isn’t what I wanted, it’s too glossy.” The problem is not the color but the gloss. An RAL code defines the shade; it does not say whether the surface will be matt or glossy. Without both pieces of information given separately, the order is incomplete.

What Is RAL

RAL is the most widely used color-matching standard in industry. The classic RAL Classic collection fixes about 200 shades with four-digit codes: the first digit indicates the color family (1 yellow, 3 red, 5 blue, 6 green, 7 gray, 9 white/black). The most common codes in powder coating include RAL 9016 (traffic white), RAL 9005 (jet black), RAL 7016 (anthracite gray) and RAL 7035 (light gray).

The purpose of the code is to make words measurable. “Gray” is a different shade for everyone; RAL 7016 is a single reference. Still, the code alone is not enough. RAL Classic is a color number; gloss, texture (smooth/textured), effect (metallic, pearlescent) and resin type are separate items. You can order the same RAL 9005 both dead matt and glossy; both are correctly “RAL 9005.”

The color on an RAL fan deck is printed or on plastic; the cured surface of a powder coating can look different. On critical jobs, approve color not by RAL number but with a cured sample of the actual powder (same resin, same gloss). The exact shade varies with the formulation and curing conditions, so it is important to cure the sample part under the same curing regime as production.

Gloss

Gloss is the degree to which a surface reflects light specularly (directionally). It is measured with a glossmeter: the instrument directs light at the surface at a defined angle and reads the reflected light, giving the result in gloss units (GU). The standard measuring geometry for powder coating is generally 60°. 85° is used as a complement on very matt surfaces to sharpen the distinction, and 20° on very glossy surfaces.

Whether a surface counts as “matt” or “glossy” depends on this GU value. The bands below are practical ranges widely used in the industry; exact limits may shift by a few units between manufacturers.

A single reading is misleading in gloss measurement. Take readings from several points on the flat central area of the part and average them; film behavior is different at edges and corners. Verify the glossmeter on the calibration tile supplied with the instrument before starting work. GU deviation usually comes from the formulation lot, curing temperature or film thickness: the same powder can give a different gloss when undercured.

Color Perception

Even when the code matches, two parts can look different to the eye. There are several field reasons for this. The first is metamerism: two samples match under one light (e.g. daylight) but diverge under another (store fluorescent, incandescent lamp). Always approving color in a standard light booth close to the lighting conditions where the part will be used reduces this risk.

The second is lot (batch) variation: powder with the same RAL code from different production batches can carry a slight shade difference due to small deviations in pigment dosing. On large jobs that must look uniform (such as adjacent facade panels), work from a single lot where possible and maintain lot traceability when blending leftover powder.

The third is the effect of gloss on shade perception. The same RAL 7016 is perceived as darker and “fuller” when produced matt, and lighter and more vivid when glossy because of surface reflection. So when a customer says “the color has changed,” it is often the gloss that has changed. Keeping shade and gloss as two separate specifications largely ends these debates. Color selection must also be considered together with resin; the same pigment can give a different shade and gloss across powder types.

Gloss and Durability

Gloss is not just about appearance; it also affects service life. Because matt surfaces are micro-rough, they make fingerprints, water spots and dust pickup more visible; cleaning is more laborious and scratch marks are easier to notice on a matt base. Very glossy surfaces, on the other hand, magnify every irregularity: slight orange peel, sagging or substrate marks are immediately visible in a glossy film. That is why a glossy finish makes the job harder when surface preparation is weak.

Outdoors, a separate issue comes into play: gloss loss (gloss retention). UV and weather erode the resin from the surface; first gloss drops, then chalking and color fading follow. A surface with high initial gloss shows a more noticeable absolute change even if it suffers the same percentage loss. If you want permanence on an exterior facade, consider the gloss choice together with resin durability; we cover this relationship in detail under UV and gloss loss.

• Interiors where cleaning matters: the semi-matt/silk band strikes a good balance between stains and scratches.
• Architectural anthracite look: matt/dead matt is preferred; pay attention to surface preparation and curing stability.
• Long-life exterior facades: choose a polyester/super-durable resin resistant to gloss loss and verify the target gloss on the manufacturer’s datasheet.

In short, RAL and gloss are two separate decisions. The code fixes the shade; the gloss value defines the surface. When you place the order stating both, e.g. “RAL 7016, semi-matt, ~40 GU,” most color disputes with both the manufacturer and the customer are resolved from the outset.