I wanted to make a tulle for my project. Made this simple material (attached). but when i tryed to change parameter of refraction nothing happend. Tulle, no matter 0 or 1 in refraction param, still looks like glass. I searched what could be the problem and when i switched off post process all started look normal and refraction parameter again started to work. I found out that its raytracing translucency makes it look so unreal and makes refraction parameter useless. When translucency raytracing is on refraction parameter doesnt change anything at all.
You need to use specular, not the refraction. Refraction doesn’t work with ray-tracing. If you try to change refraction values in the material editor, you will see a change. The reason is material editor is not using ray tracing.