I find Copolymer right slippery and therefore always tuck my blood knots
Yes, that's an interesting one Steven.
When I was doing the R&D for Troutcast Tippet, I had manufacturing options of lubricated or non lubricated materials. I'd had problems in the past with copolymer knots slipping, so this comparison process was interesting, and I found that my problem went away with a non lubricated product. ( which also explains why I wet my knots, I fish a non lubricated product
)
But, as I've said before, tippet/leader materials are very much down to personal preferences!