Inspired by Jørgen @Holo complaint on the OpenGL transparent materials, here’s something I’ve been meaning to report for a while. If the groundplane is visible through a transparent material, it looks as if the groundplane material is overridden by a default material. Is this something that can be changed/tuned up, or does it have to do with the weakness of the shadow catcher material - I seem to remember you indicating that it’s not really a “proper” Cycles solution? Attached is the same view with the groundplane as the default plaster material and the “shadow only” material. Notice how the groundplane - when seen through the glass - is the same on both screen grabs.