I've used 2 layers of W&N and hand quilted that puppy. Would NOT recommend that adventure for the faint-hearted. But I think you should be fine tieing 2 layers. If you have a curved upholstery needle, I'd suggest using that to work through all over your layers if you can. Plus the eye's are larger on those needles if you're using yarn. And save yourself - use a thimble to push. Even if thimbles are uncomfortable for you - use it! Your fingers will thank you in the long run.