Since "deep paper" does not appear in the official changelogs from Dotec , it could be a mistranslation or a niche term used in specific community "skin" or "texture" packs. In the context of vehicle simulation:

The (v1.6.3 for game version 1.46) is a highly detailed community mod for Euro Truck Simulator 2 . While the phrase "deep paper" is not a standard feature or technical term associated with this mod's official documentation, it most likely refers to a specific dashboard or interior material texture within the mod's customization options . Mod Features (v1.6.3)

: It might refer to a Normal Map or Bump Map applied to a paper-like material (such as a dashboard cover or a specific trim) to give it a 3D, "deep" appearance.

In the 1.6.x series of updates, the mod received several enhancements that impact the "look and feel" of the truck's interior and exterior:

If you are looking for this specific material, check the section in the Truck Upgrade shop under the "Dashboard" or "Exclusive" variants.