Glass-Etched Reticle
A reticle etched directly onto a glass plate inside the scope, allowing intricate grids and clean illumination that thin wire cannot provide.
A glass-etched reticle is acid-etched or laser-cut into a flat optical plate rather than formed from strands of fine wire suspended across the tube. The glass support lets manufacturers draw far more detail than wire allows, which is how dense holdover grids and a full christmas-tree-reticle become possible without anything sagging or breaking under recoil. The trade is a very slight light loss from the extra glass surface, generally invisible in practice on a quality optic.
The etched approach also makes an illuminated-reticle practical, since a light source can glow through the engraved pattern to brighten only the lines that matter. These reticles appear in both focal planes, though the busiest tactical grids usually live in the first-focal-plane so their subtensions stay true across the magnification range. The durability and design freedom together have made etched glass the standard for serious precision scopes.