I would appreciate if someone could give me a hint why when using Decal for putting sticker on the object image is visible on both sides of mesh?
Here is the sandbox https://codesandbox.io/p/sandbox/decal-on-mug-ty2xgf?file=%2Fsrc%2FApp.js
The decal gets applied to all the geometry within the box you supply.
You may want to split your mesh into an inside part and an outside part of the cup and only apply decal to the inside part.
@manthrax thank you so much. That did the trick
Here is a blender screenshot if someone came across similar problem.
PS. very messy mesh selection but just enough for proof of concept