Finally remembered the name - Araya Tita-Ace - from the early 1980s. I never owned a pair but saw them very occasionally and always thought they looked cool in their distinctive titanium colour. With no factual basis in research I considered them an aluminium rim with some essence of titanium sprinkled into the alloy, or perhaps just the anodising, but for all I know there may be more to them than that.

For the truly committed it seems they are available NOS for no more than many current carbon fibre rims…

https://alexscycle.com/collections/n...d-32h-rim-pair

Thats about USD900- per pair by my reckoning. I have no affiliation with Alex’s Cycle other than as an infrequent customer.