Could not find a post on this, so doing one. Dupont/now 3M Kapton (reg. trademark) tape has a Chinese knockoff on the market, on eBay and perhaps other sources (?). It's branded only on the leading edge of the tape, "Koptan", so once you remove that and start using it there is no marking whatever on tape or roll. It is sold as of my eBay order from a "Wang" at a private mailbox address in Walnut CA, advertised on eBay and stated on the invoice as well as "Kapton" (the brand) but that is not what I got for my 8.98 free shipping order!
It's stated to be 1 mil film with silicon adhesive, which matches the 1 mil Kapton brand description. Search on Google for "counterfeit Kapton tape" and you'll find a number of posts. Some say the "Koptan" is OK for what they use it for. I didn't see any uses that clearly matched what we might use Kapton to do, i.e. very thin but very tough, tightly sticking, but removable without residue, and very high electric insulation (dielectric) value for its thinness.
So I did what I should have the first time, ordered from ULine (in my case) the thicker 2 mil film Kapton brand which may not be absolutely needed, but will be easier for a novice user not to tear while applying to a project.
They have a ton of listings for it: 