I have both poly and thin skin.

I wouldn't suggest any strong tapes/glues on poly as cleaning is kind of a hassle. Guess it also depends on how much you sweat and how long it stays on your scalp. For poly units, I cut the tapes (all tapes are invisible since it is under the poly) into small pieces and attach to different corners (one at the front, two on the temple sides, one long strip in the mid-section, one small piece on the left and one of the right and you may want to use one whole strip on the back so that they hold better) and then apply glue across the front. First day may not be strong but it gets stronger each day since we perspire and the oil sebum strengthens the poly (it really sucks on your scalp). I remove it every two days otherwise my scalp will get freaking irritated, especially when I am asleep because the tapes do break down.

For thin skin, it is much easier to clean up and it holds as well as poly (can be stretched too) but more fragile (got to handle carefully). I work out a lot and I do not keep it on for longer than two days.

Thin skin with injected knots are extremely natural but "screeching" sound (when you scratch your scalp) is a bit different from our real scalp (lace sounds the same). To the touch, lace is better but you can't remove as and when you feel like, especially those whose scalp gets irritated easily.

Just my personal preferences and opinions ;-)

Greenery