Blender 5.2 adds a new Thin Wall option to the Principled BSDF.

When Thin Wall is enabled, the renderer treats the object’s surface not as the boundary of a thick solid with an interior volume, but as a single, extremely thin sheet of material.

It is useful for materials whose actual thickness is difficult or unnecessary to model, such as paper, leaves, and thin glass panels.

Representing a Single Surface as a Thin Material

Previously, creating a thin transmissive material often required adding actual thickness to the object or combining several shader nodes.

With Thin Wall, even a flat surface with no thickness can be treated as a thin sheet material.

This makes it easier to create thin materials with transmission and reflection without adding a Solidify modifier during the modeling stage.

Good examples include:

• Paper and thin wrapping material
• Leaves and flower petals
• Thin fabric and curtains
• Vinyl and film
• Window glass panels
• Thin membranes such as soap bubbles

https://vimeo.com/1213436573/03ced0c292?share=copy&fl=sv&fe=ci

How Is It Different from the Previous Method?

Previous Method