Talk:Glue/@comment-33013786-20180608190808/@comment-32444969-20180608235143

https://devforum.roblox.com/t/introducing-new-material-glass/64231

"Non-opaque objects are currently not visible through glass. This includes, but is not limited to, transparent parts, decals on transparent parts, particles, and world-space gui objects. This behavior matches the refraction on high quality smooth terrain water. This was implemented so refraction wouldn’t have a large performance impact. This behavior may change. We do not recommend relying on this behavior for gameplay."