Quote Originally Posted by Sal Santamaura View Post
...Apparently, when there's a unique need for an oxygen barrier, PETE is used.
Quote Originally Posted by Ian Grant View Post
That also goes for HDPE, in the case of the Legacy Pro product it's more likely cost in their choice. Ilford and Agfa (and successors) sell their liquid ascorbic based devlopers in HDPE...
According to this

PET passes less than 1/8 the oxygen that HDPE does. I'm not sure what relative costs are, but, given that HDPE is ubiquitous and PET isn't, suspect the latter is more expensive, not less.