In this particular example, I have chosen to show how to create a lamp shade material using the “vray 2 sided material”, but you can create other type of similar materials like translucent paper, thin cloth, etc., following the same method.
1) Select your geometry and apply the vray2sidedMat to in, in the material editor.
2) Choose a light grey for translucency. A black value shows the front material (no translucency), while a white value shows the back material (100% translucency).
3) Click on the front material, and assign a vray material with the desired maps for the diffuse and bump slots. Do not assign a back material; leave that slot un-ticked.
4) Place a vray light (sphere) in the center of the lamp shade and scale it vertically.
5) Experiment with the vray light size and multiplier, and the translucency parameter until you obtain the desired result. For this particular scene I used a vray light multiplier of 8, and 201, 201, 201 for the RGB coordinates of the grey (translucency control) but these particular settings may vary depending on your scene, lighting rig and rendering setup.