The finish changes how a roof reflects light and the product warranty conditions. Gloss gives visible reflections, while matt finishes show the profile more subtly.
For the verified models, BILKA lists 10 years for Gloss, 15 for Matt and 30 for GrandeMat, covering colour and corrosion under its certificate. These figures do not replace the conditions for the configuration ordered.
Colour ranges differ. A shade available in Matt may not exist in GrandeMat. Choose the model and finish first, then check the shade on a physical sample.