From the pattern:

Temptation is a unique Japanese silk yarn, made with unspun reeled filaments of Tussah silk barely twisted. It is very fragile, so make sure your nails and hands are smooth. But don’t put lotion on your hands right before using it, or it will stain the silk. The yarn may snag, but if it does, ignore it and move on. When you finish, move all the snags to the back of the work with a crochet hook. Because the yarn is barely twisted, it may split, so make sure your needles are ultra smooth and not too pointy. I suggest metal or plastic needles, such as Addi Turbos or Pony Pearls. If you use wooden needles, I suggest you use needles from Lantern Moon. But even with the smoothest needles, splits may occur. If so, redo those stitches and move on. Do not fret; although this may seem onerous, the results are worth it!