Every fabric reacts differently to heat, but in no fabric does an iron at 200°C have no consequences.
Silk and wool their protein fibers. Above 150°C, the protein chains begin to break down. With silk, this creates that shiny spot that never goes away. Wool loses its resilience and becomes stiff and lifeless.
Polyester, nylon, and acrylic melt slightly on the surface at excessively high temperatures. The subtle shine after a few ironing sessions? That’s the fabric literally melting. Acrylic deforms starting from 100°C.
Viscose weaken with repeated heat and lose their soft drape. Cotton and linen are more heat-resistant, but here too, pressure and heat over time cause wear.
What remains is permanent damage. Invisible until it’s too late.