Which security feature is described as changing color with the viewing angle?

Which security feature is described as changing color with the viewing angle?

• A. Hologram (kenogram and infogram)
• B. Optically Variable Ink (OVI)
• C. Watermark
• D. UV ink

Answer: (A)

The feature described is an optical variable device, with holograms being the classic example. Holograms use microstructured surfaces that diffract light, so as you tilt or view from different angles, the image and colors shift. Kenogram and infogram are specific hologram types designed to show these angle-dependent color changes, making them easy to verify visually. Watermarks are static images visible when held to light, not color-changing with angle. UV ink only reveals under ultraviolet light. Optically variable ink also changes color with angle, but the familiar, widely used angle-changing security indicator on many items is the hologram.

The feature described is an optical variable device, with holograms being the classic example. Holograms use microstructured surfaces that diffract light, so as you tilt or view from different angles, the image and colors shift. Kenogram and infogram are specific hologram types designed to show these angle-dependent color changes, making them easy to verify visually.

Watermarks are static images visible when held to light, not color-changing with angle. UV ink only reveals under ultraviolet light. Optically variable ink also changes color with angle, but the familiar, widely used angle-changing security indicator on many items is the hologram.