Sounds like heresy, doesn't it?
On the DIY Channel program 'Cool Tools' there was a segment on Shurtape's Razor Edge Gold premium masking tape (CP-60).
From the description & video it sure looked & sounded like Tamiya's masking tape. I googled and found the product spec, and this afternoon I hit a couple of the paint supply shops in the area.
I found some at the local Sherwin Williams store. It comes in 3 different widths on standard masking tape cores. I picked up a roll of 1 inch X 60yards (24mm X 55m) for about six bucks.
It is the same material as Tamiya tape, same paper, adhesive, flexibility. Shurtape says it can remain on for 60 days.
It has the benefit of being less expensive than the Tamiya. A quick search of the SMO website showed that an 18mm X 18meter roll of tape cost the same as the roll of Shurtape's tape, for 3 times the quantity. Narrower strips can be cut with an Xacto & a straight edge.
Once again it pays to shop around and not limit your modeling purchases to only those items with a model manufacturer's logo.
Oh, and for those of you on the continent, Shurtape looks to be a European-based company so you should be able to find it through distributors over there.