This was a question that could have gone into a dozen different forums. Like you said hopefully the right guy will come along that can explain what characteristics give these materials and coatings their unique tactile properties.
You can use a very soft material, e.g. for a soft touch handle inside a car back seat but then it's too soft to bear load. So what they do is to use a hard, load bearing material and put a soft touch coating on it. For example a paint containing soft touch silicone particles like these: