Glass and transparent materials in PBR are mostly shader work, not a stack of colorful JPEGs. Clear window glass has almost no albedo texture. Frosted shower glass, cathedral pattern, wire mesh, and dirty storefronts do need roughness and normal maps. This article separates “pure glass” from “textured glass” so you stop plugging a gray photo into Base Color and wondering why the pane looks like plastic.
When glass needs textures
Use a texture only when the surface has spatial variation. Frosted privacy glass needs a roughness map (and often a mild normal). Ribbed or fluted glass needs a directional normal so highlights travel along the ribs. Wired glass needs a metalness or color mask for the wire. Dirt and rain streaks belong in roughness and a subtle albedo tint, not in a baked photo of a sky. For flat architectural windows, skip image textures and spend the time on IOR, thickness, and the HDRI. Browse glass on Locker3d when you need those patterned or frosted maps; keep metal for frames and hardware.
IOR, transmission, and roughness
In Blender’s Principled BSDF, turn Transmission up (1.0 for solid glass). Set IOR to about 1.45–1.52 for soda-lime architectural glass; acrylic sits nearer 1.49, water 1.33. Roughness near 0 is optical clear; 0.1–0.3 is lightly etched; 0.4+ is privacy glass that no longer shows sharp refraction. Color sits in Base Color as a slight tint, not a photograph of the room behind the glass. Metalness stays 0. If you need a recap of PBR slots, use the complete PBR textures guide. In Unreal, use a Translucent or Thin Translucent shading model and drive roughness from a texture only where frost exists.
Thin glass versus thick glass
A single plane with Transmission looks wrong in close-ups: there is no second surface, so refraction and edge darkening fail. For bottles, vases, and shower screens, give the mesh real thickness (even 4–8 mm) or use a solidify modifier. For distant facade windows, a thin-glass or “transparency only” setup is cheaper and looks fine because the camera never sees the edge. In Cycles, raise max Transmission bounces (8–12) or interiors go black. In Eevee, enable refraction in the material and in Render Properties, and keep roughness low or Eevee will smear. Product shots of perfume bottles need thickness, a correct IOR, and a studio HDRI—not a 4K “glass texture” downloaded as albedo.
Frosted, patterned, and dirty glass
Author frost as a grayscale roughness map. White (rough) hides the interior; dark (smooth) keeps a clear stripe or logo. Tile the frost at a scale that matches sandblast grain—usually much smaller than a brick texture. Patterned glass: keep albedo almost white or very light gray, put the pattern in normal/height, and keep roughness mid so the pattern reads in specular. Dirty glass: multiply a faint dirt albedo, raise roughness in the same mask, and avoid putting dirt in the normal unless it is thick grime. Apply maps with the color-space rules in how to apply PBR textures in Blender: roughness and normal are Non-Color.
Frames, interiors, and CC0 sources
Glass never sits alone. Pair panes with wood or metal frames from the Locker3d catalog, and light the room behind the glass or the pane will render as a dark hole. Locker3d glass-related maps are CC0, so you can ship them in commercial archviz; details are in CC0 textures: what you can and cannot do. More setup notes are on the blog. Do not use random “free glass PNG” sites with unclear licenses when a CC0 roughness map plus a Principled shader already solves the look.
Frequently asked questions
Do I need an albedo texture for clear glass?
Usually no. Clear glass is a shader: transmission, IOR around 1.45–1.52, and low roughness. Use textures when the glass is frosted, wired, ribbed, or dirty.
Why does my Blender glass look black?
Transmission needs enough light bounces and a visible environment. Raise Transmission bounces, add an HDRI, and use a solid or extra thickness—not a one-sided plane—if you need refraction.
Can I use Locker3d glass textures in commercial work?
Yes. Locker3d maps are CC0. Combine them with your own glass shader for windows, showers, and product bottles without royalties.