They are the same exact fibers. For instance the EK Adornments line is mostly Trendsetter yarns at over inflated prices. If you knit, you should know how to check for color fastness. If you are very worried about archival issues I don't know what to tell you. The PH should be fine, it is not really acid content that you need to worry about here. But, many of the man made fibers (polyester and such) could be made of the 'bad' plastic that gives off a gas that can damage photos. Also the metalic fibers could be abrasive. However let me restate, the "scrapbook" fibers are not anything special and are not made exclusivly for the industry...