Fully micro-optic security document

A security document, comprising:

• a secure substrate, the secure substrate comprising a viewing side and a backing side, and a micro-optic system having microstructures integrated within the secure substrate comprising a single layer, the micro-optic system providing an optically variable effect on the viewing side, wherein the secure substrate including the integrated microstructures provides a structural foundation for the security document;
• a protective layer,
• wherein the microstructures of the secure substrate comprise:
• focusing elements, wherein the focusing elements appear transparent on the viewing side, and wherein the focusing elements reflect, refract or provide an interference effect in light passing through the focusing elements;
• image icons;
• and
• a machine-readable security feature;
• and
• an optical spacer within the secure substrate,
• wherein the layer of focusing elements is disposed on a first side of the optical spacer, and wherein the image icons are embedded within the optical spacer, and
• wherein the layer of image icons comprises image icons disposed proximate to focal points of the layer of focusing elements.