Hi Jason,

I'm not sure if you CAN properly tie a blood knot using backing and fly line? I would think the difference in line diameter would be a headache. Would it hold??? Probably. Could you tie it?? Never tried. Do yourself a favor and try to learn either the Albright or Nail knot. A little trick with the nail knot.....use a piece of a ball-point pen ink tube (obviously, without the ink ) to feed the backing thru. Works for me. Leave the blood knot for tippets. Glad to help with the backing and line. Happy New Year to you, too.

Ken