Shower glass must be safety glass in virtually every jurisdiction — tempered (fully toughened) is standard, breaking into small granular pieces rather than sharp shards if it fails. Thickness for frameless panels is typically 8-10mm; framed or semi-frameless screens can use thinner glass because the frame adds support.
Low-iron glass is often specified for shower screens because standard glass shows a green tint at the thicknesses used for frameless panels — low-iron keeps the view genuinely clear rather than tinted.
Hard water and coatings
Water spots are mineral deposits left behind as hard water evaporates on the glass — a maintenance issue, not a defect in the glass itself. Factory-applied hydrophobic or anti-limescale coatings reduce spotting but wear down over years of use and cleaning.
A daily squeegee after showering remains the single most effective habit for keeping any glass screen clear, coated or not — coatings buy time, they do not eliminate the need for routine wiping.
Frameless vs framed
Frameless screens use thicker glass and fewer seals, which means less grime-trapping trim but a higher glass cost and a heavier installation. Framed and semi-frameless screens cost less and can use thinner glass, at the cost of metal trim that needs its own cleaning and can corrode over time in humid rooms.