The best that I'm able to compare it to is an analogy. You know when you shake hands with someone, or share a hug with them that you can, at times, get a sense of them by how they do it? Well, I get texture from someone in a similar way but it's rather more detailed. It's not really something that comes in through the skin or other similar avenues, it's just something that I know when I meet the person or think of them later. Unfortunately, I don't have the words to describe the words that would describe the textures. Some people are obvious but to describe them in normal texture words like slick or comfy is to vastly oversimplify. It'd be like describing all of Freudian analysis as "there's the id, ego, and superego and drives associated with those".