A holo (short for holographic) is a trading card whose image area is printed on a foil substrate, producing a shifting iridescent pattern when the card is moved through light. Holographic printing was introduced commercially to trading cards by Pokémon’s 1999 Base Set and rapidly became the standard high-rarity treatment across virtually every modern TCG. In the Pokémon framework, a holo is the primary rarity tier in older sets, marked with a black star symbol; modern sets distinguish multiple holographic patterns including cosmos, crosshatch and full-art treatments.

Grading holographic cards requires care: the foil surface scratches more easily than a standard card and shows light-refraction defects that ordinary cards do not. Top grades on vintage holos are correspondingly scarce, and the centring tolerance is often the tightest variable.

Holographic foil treatments have been a defining visual element of trading cards since the 1990s. Modern holographic patterns are produced by embossing a fine diffraction grating into a metallic foil layer that is then laminated onto the card stock. Different patterns produce different visual effects: cosmos holo (small star points), sheen holo (smooth rainbow), galaxy holo (swirled colour), and etched holo (textured surface) are among the variants used across Pokémon, sports, and gaming card lines. See our reverse holo entry for the variant treatment.