glass refracts at 1.5 not 1.05 no you dont need to use a an MR shader with nurbs, you can use whatever you like it was a suggestion J In this hourglass' case I just needed a certain type of refraction so it would not morph the sand inside. If I try 1.5 the result is pretty weird. I mean look at how the refraction is on these real hourglasses: This one might be CGI, not sure, but this is the type of refraction I want to have, and 1.05 looks good, if only it didn't take away the specular with it.