Maximum page count with premium paper?

Hi all:

I know this has been discussed in the past, but I’m still not clear on the page limits.

I’m currently working on a large landscape book, 12″ × 12″.
When I go over the 160 page limit, I get a warning that I can’t use premium paper. However, in the “Books & Pricing” section of the Blurb website, it shows pricing for premium paper up to 240 pages.

So, which is correct?

thanks
S

Thanks Nik:

That is precisely what my problem was.

regards
Sangio