A high-precision marker, which is easy to manufacture, has a base material layer, a first layer which is laminated onto one surface of the base material layer, and which is observed in a first color, and a second layer which is partially laminated onto the first layer, is observed in a second color different from the first color, and partially conceals the first layer, wherein the first layer is observable in a region in which the second layer is not laminated, and the second layer is formed by a resist material.

A protective element, including at least one first layer and at least one second layer. The first layer is made from elastomeric material and the second layer forms a flame-retardant layer. The first layer can include silicone elastomer. The first layer can include a first filler, the first filler being made from inorganic material.

An example electronic device includes a transparent cover; and a flexible display coupled to the cover. The cover may include a first layer including glass; a second layer positioned between the first layer and the flexible display; and a third layer positioned between the first layer and the second layer. The third layer includes a pattern overlapping a folding part of the flexible display and including a plurality of grooves formed in a bonding surface with the second layer, and has a hardness greater than that of the second layer.