I don't usually tie on to a previous warp unless it's something like a rug or rag weaving warp with few ends per inch. Today I decided to tie onto the ginkgo warp I just finished. I thought I'd give it a try because it's a real reach back there threading harnesses 30 thru 40. Was it a time saver? I don't think so. I can thread heddles and the reed pretty fast, tying all those warp ends might take me a bit longer.....but I gave it another try.......after all it's been a long time since I've done it and I must have forgotten it's really not a time saver for me. I would love to hear from others on how you do it quickly - maybe I'll change my mind if I change my process.