An article of transparent and brittle material, such as glass, glass ceramic, ceramic or crystals. The article includes at least one exchange layer and at least one bulk layer. The at least one exchange layer includes at least one kind of cation ionI with an increased proportion compared to the at least one bulk layer and at least one kind of cation ionR with a reduced proportion compared to the at least one bulk layer. The article is in particularly used as a display cover for flexible displays or flexible protective foils, for example in smartphones or tablets or TV sets. The article can also be used as a substrate for an electronic component such as an OLED or LED.