So I did a sofa cleaning today. I was kind of in a rush so I didn't inspect it all that closely before starting. Looked and felt like something synthetic like I do every day and pretty oily so I went ahead and presprayed with some bio-break in a pump up. I use bio break a lot because that plus citrus solv really cuts through suntan lotion that I see almost every job. While I was cleaning, i noticed these brown specks, basically all over, except it wasnt really on the bottom front of sofa or the backside. And some sides of cushions had very little. As soon as I finished extracting I thought maybe there was some natural fabric mixed in, so I sprayed the entire thing down with Fabset and did a dry vacuum of it all. It didnt really help much. Customer said she was just glad it was clean and that she probably wouldnt really notice it. Anyways, it may have been there before starting. Any idea what causes this? This is in a very humid area close to the beach.