The new invisible threads are much softer and more pliable than the old fishing line.........I think thread type/usage, like prewash or not, glue/pins, etc., are all personal choices and some are even new discoveries, so to speak.....I do not have the book referred to, but if I question something I read, I contact the author and ask for reason why statement was made, or source of that information. I have the same issue, personally, with using muslin on backs of quilts....my preference.and recently read an article in a current mag about how "cheap" muslin is and she definitely does not recommend....I have an issue with that statement and I shall contact her with my opinion. Like all things we read/ hear/see......believe half.....