This is one of PFCs detailed celtic knot designs. It's best suited for stitching on an evenweave (and rare for one of my charts, it needs to be stitched over 2 for most of it, as there are petite and partial stitches included). To get the depth of shading I'd recommend choosing some suitable silks (hand dyed ones look amazing). Make it your own with fabulous colour choices (although I have included a few suggestions if you want to match the pic on the front).