Gloss is measured by the percentage of light a surface reflects. Matte is roughly under 30%, semi-gloss sits between 30–70%, and gloss is above 70%.
Gloss surfaces look sharp and clean and are the easiest to wipe down, but they also reveal every dent, weld mark and flaw in the metal underneath.
Matte surfaces hide surface irregularities and fingerprints far better, which is why they dominate architectural work and interior metalwork. In return, buffing out scuff marks is harder.
Textured powders give the film a fine surface pattern. This pattern nearly hides small flaws in the substrate and noticeably improves grip — the usual choice for railings, hand-tool housings and outdoor furniture.
Rule of thumb: choose gloss where cleanliness matters, matte where the surface should visually recede, and textured for parts that are handled or take stress.