Tesa 4289 tape. It just happens to be perfect for tubeless setups.
It is a high tensile polypropylene strapping tape that is self-adhesive (it sticks to rims well). It conforms to tubeless rims well but is best applied under tension.
Thickness is 0.144mm and the adhesive is natural rubber.
This performs as well as the leading tubeless tape which is also a strapping tape.
Roll length is 66mm. Width is 21mm, 25mm or 32mm.
21mm tape is great for rims between 17mm and 19mm internal width.
The depth of the well in the rim affects what width tape is needed. BORG50C, BORG45DISC, BORG22' BORG31 with a 19mm internal width require 21mm tape.