Effect

Liquid glass frost

The backdrop behind the glass turns into soft colour, with a faint grain; edges still bend. Reads as sandblasted or milky glass.

Also called blur, frosted, haze, diffusion

A frosted rounded pane over dunes and sky, with the dune bands blurred inside.
A frosted rounded pane over dunes and sky, with the dune bands blurred inside. (light)

Where to use it

Use in
Large and text-heavy surfaces: dialogs, sheets, sidebars, long menus, notifications. Small controls get almost none.
Avoid
Frost without refraction and rim (glassmorphism card); frost so strong the colour from behind disappears; greying the backdrop.

Parameters

blur 0.5–1 (lens), 1–4 (regular), 8–16 (frost); grain ±1–2 px UV jitter; fill white 20–30 % light / black 30–40 % dark.

How it is built

Design tool
Figma Glass: Frost 2–20. Manual: background blur 3–24 + fill 20–30 %; optional 2–4 % noise layer.
Web
feGaussianBlur after feDisplacementMap inside the same filter; fallback backdrop-filter: blur() saturate(1.5).
Shader, in one line
jitter the sample position with hash noise (±1.5 px) and average 4–13 taps around the refracted position; mix with the sharp sample by the frost amount.