It cracks me up how you guys take it so seriously :))))
But that’s the whole point isn’t it? Now go dial some red into the green 
hang on, must go and google what you mean by seriously.
We had a job like that a while ago from a pharmaceutic company who had some brilliant idea for their next print ad. They wanted a newton’s cradle made out of water and the spheres at the bottom should be a water shell filled to around 50-60% with water in a completely white circular clinical room. They gave photo reference of a lot of highspeed water photography showing the look of what we were supposed to achieve. They made some snarky comments about how the client is very knowledge about how water behaves etc. and that it had to look photoreal. In the following 2 month we spent in a constant back and forth between them and us telling how refractions and reflections were all wrong (they weren’t at least from an objective standpoint). In the end we had to kill all refractions etc + some real weird photoshop stuff to finally satisfy the client. The end product looked like a bad photo collage of elements without any realism and internal logic. But apparently the client loved it.
Half a year later we stumbled onto the picture we did but heavily modified the geometry etc and all were the same but the water constructions were made to look like chrome.
Personally this was the most frustrating client interaction I have ever had.
@Dmitry
We still love you.
Lol.
Some one referred to the “sheen” term as a render man value. Well, it’s all good, if the client had slightest clue how a shader worked, let alone a render man shader :)))
Isnt it called coating in cg?
Now the LAPD is involved…CNN
I saw the headline today and thought they were speaking to us…
One of my biggest client issues is when they try to run the show. I give them the schedule, the process, and they assume that it is suggestions, or something. I model the building and get feedback before I model the site. The site is usually more complicated and takes a lot of work. If the building changes then you have to rework a lot of the site. Today, I sent a building for proof and the architect’s reply was, “I don’t want to see this again until the site is done!” Really! I’ll email him in a few days asking for the building comments 
“I want the glass MORE seethrough and a LOT more reflective”
“Can you add some SHEEN to the floor tiles” > “Why does the floor look so slippery?”
Yeah, get that one a lot. I also get the similar…“can you make the glass more see through but we don’t want to see anything on the inside.”
Vlado can we add sheen parameter to vray Mtl?
And have a parameter that we can edit the label, according to what the client likes to call it
I am going to play devil’s advocate… I find that it is just as common for the artist producing the scene to not understand what is being asked as it is for the client asking unreasonable things.
Indeed, although I think its commonly down to the client not being able to explain what they want. I always get clients to send me reference imagery for anything that seems a bit odd, and more often than not they are using incorrect terminology so we are misunderstanding each other.
I have one designer that consistently uses Opaque to describe Translucent material for example, but now I know what he means.