I am trying to make it just as exercise but I can’t obtain a realistic result.
The shape is bad and the samples are low ecc ecc (and ok), but I don’t know how to set the fabric. If I increase the density, it becomes more dense, but still I can see what is behind and I don’t want to see sharp shapes; instead, I want to see only diffuse lights, keeping a decent amount of light.
While I want to obtain this effect: https://www.outletarredamento.it/img/illuminazione/lampada-epoque_N1.jpg Any idea?
For most objects, you also need to have a surface shader (if you’re new to Cycles, then the Principled Shader would be a good choice as it also allows transmission effects).
This scenario is pretty much what the Translucent shader was designed for.
Diffuse (and glossy?) - For the inside.
Diffuse (the direct light from other lights) and translucent (affecting the “rear side” diffusely) - For the outside. If you want the shade to be partially transparent, you need to mix with a transparent shader as well.
You probably also want to do a complete override for the shadow using transparent shader at the end shader mix controlled using isShadowRay.
I also tend to add emission to the shade as well if that fake does it good enough. Strong emission for the inside and a weaker emission for the outside, with no internal “light bulb/source” at all. Good enough for me may not be good enough for you, but I prefer manageable speed and less noise compared to physical accuracy.
Hey thanks to all, it worked with Traslucent shader! 
I am relatively new to Cycles, I am just doing some exercices and attempts.
I have added diffuse+glossy inside and transparent too, as suggested…
I strongly reccommend faking the light shade though, as you get cleaner results much faster. Especially if it’s “just a prop light”. For a product render of the lamp shade, that’s when you’ll want to add some better realism to it.
Here is how I would set it up, although the 1/IOR trick you don’t need at all if you want to omit the glossy component (only for glossy paper shades, I probably wouldn’t use it for a fabric shade). The inside colour influence(colour) the outside colour, just mute that multiply node if you don’t need that. Turning on or off the (fake) “light” inside is just a matter of muting and unmuting the two red nodes. Teh “bulb” colour temperature can also be controlled.
Thanks CarlG! Now I am not at the level to understand all the nodes so clearly but anyway keep the images on the thread so that I’ll consult it again in the future to understand it better when I’ll be more skilled.
Many many thanks!
