So just bought myself a Saracen Levarg gravel bike and am looking at doing the tubeless conversion. The rims are JALCO 27.5 with Maxxis. I haven't done a gravel wheel set, so what rim tape are people using? I was thinking of 25mm tape, but didn't know there were so many different rim tape widths now!
I think 2-4mm wider than the stated inner width of the rim seems to work, most of my rims are 20mm internal and I usually use 25mm tape.
I had a really awkward rim recently, the rim bed shape was relatively intricate with quite steep sides so several different tapes struggled to stay put. I found black tape like (from memory) Vittoria, Pacenti and DT seemed thinner and could conform slightly better, but beware that the DT tape doesn't like ANY tension, mine tore the second I pierced a hole for the valve.
The Giant bronzey coloured stuff is supposed to be good, a bit more flexible and a bit stickier.
This stuff from Banana industries work well on the last set of wheels that I taped
TESA Tubeless Tape 66m 21mm or 25mm — bananaindustries https://share.google/uMmi4TVwMGLbbJ4yY
The Tesa tape as above although I would look at ebay for a better price or aliexpress. Anything else is paying for a name. To be honest it doesn't really even matter what width. All you are doing is sealing the spoke holes and dealing with any vagaries between the rim and the tyre .