Comments about Scotch 810 Magic Tape Refill, 3/4" x 36 yds.:
Priced by the yard, these single 36 yard rolls are usually a better value than the 3 packs of 27.7 yard rolls.
As for being "invisible", that depends on what you are taping. With regular paper the tape is barely visible after applied. However, with semi-glossy paper (such as wrapping paper) the tape really shows. For wrapping I prefer the tape strips (Item #440433.)
CON: The 3 rolls I received were poorly rolled/cut. That is, the sides were not smooth. One did not turn well in my LIFESAVER shaped dispenser which has little room for error over the 3/4" width with large rolls. The other two rolls were similarly cut, but they still turn. And the worse cut roll worked in another dispenser.