A starting material for a value document, comprising a security element in the form of a strip for use as security threads in value documents, such as banknotes, wherein the security element has a first degree of reflection for visible light on a first surface, wherein the first surface of the security element is provided with a cover layer in at least one first longitudinal portion, said cover layer having a second degree of reflection for visible light which is greater than the first degree of reflection of the first surface, while the first surface is not provided with such a cover layer in at least one second longitudinal portion, and wherein at least one first longitudinal portion of the security element which is provided with a cover layer is covered by a portion of the starting material at least in some regions while at least a second longitudinal portion of the security element which is not provided with a cover layer is not covered by a portion of the starting material or such a second longitudinal portion is only covered by another portion of the starting material with a smaller thickness than the portion of the starting material which covers at least one first longitudinal portion of the security element provided with a cover layer, characterised in that the length of the first longitudinal portion of the security element which is provided with a cover layer corresponds to the length of the portion of the starting material which covers this first longitudinal portion, wherein the first longitudinal portion does not project substantially beyond this bridge region or runs substantially entirely through it, while the length of the second longitudinal portion of the security element which is not provided with a cover layer corresponds to the length of a window of the starting material, which either forms in the starting material a continuous cutout, which is arranged above the security element, or is formed by a further portion of the starting material with a lower thickness than the portion of the starting material which covers the first longitudinal portion of the security element provided with a cover layer. wherein the first surface of the security element is provided with a cover layer in at least one first longitudinal portion, said cover layer having a second degree of reflection for visible light which is greater than the first degree of reflection of the first surface, while the first surface is not provided with such a cover layer in at least one second longitudinal portion, and wherein at least one first longitudinal portion of the security element which is provided with a cover layer is covered by a portion of the starting material at least in some regions while at least a second longitudinal portion of the security element which is not provided with a cover layer is not covered by a portion of the starting material or such a second longitudinal portion is only covered by another portion of the starting material with a smaller thickness than the portion of the starting material which covers at least one first longitudinal portion of the security element provided with a cover layer, characterised in that the length of the first longitudinal portion of the security element which is provided with a cover layer corresponds to the length of the portion of the starting material which covers this first longitudinal portion, wherein the first longitudinal portion does not project substantially beyond this bridge region or runs substantially entirely through it, while the length of the second longitudinal portion of the security element which is not provided with a cover layer corresponds to the length of a window of the starting material, which either forms in the starting material a continuous cutout, which is arranged above the security element, or is formed by a further portion of the starting material with a lower thickness than the portion of the starting material which covers the first longitudinal portion of the security element provided with a cover layer.