Hugo Nebula wrote:

Multi-foils have been caught out in recent years lying through their
teeth about the performance of their materials. Some manufacturers
have had it tested properly, and use resistance figures of ~1.7m²K/W;
YBS I notice still quote the very discredited 6.1m²K/W. Real world
testing has been done proving that anything more than 1.7m²K/W is
bull****.

"For a successful technology, reality must take precedence over public
relations, for nature cannot be fooled." [Richard Feynman]

--
Andy