I had some hand dyed fabrics a couple of years ago that I could NOT sew on my 6600P - and three of my friends could not sew it either with their 6600P. A friend of my took the fabric to a Janome store and they thought it sewed o.k. but I would never leave a seam like the one they thought was o.k. For some reason, my 9000 Janome would sew it o.k. - but that 6600P hammered like something I've never heard and just took the fabric down into the feed dogs. Never did figure out what the problem was........most batiks are o.k. but certainly don't sew like cotton. The hand dyed was a tight woven fabric like batik - I don't know if it's the dye or what. Maybe a different machine would give you better results.