Rives BFK

Just a question about RIVES BFK. Last time I bought Rives BFK the guy
in the shop asked me which one; until now I thought Rives BFK was one
of the ARCHES product called RIVES bfk, 300gms aquarel-paper with a
certain, well defined surface.
He showed me a variety of 3 to 4 papers, from 200 to 300 gms, with
different surfaces and dimensions. I bought the different Rives and
already in applying the gelatine I noticed differences. One was a bit
more yellow and was not happy with soaking. Anyway , the watermark
showed RIVES BFK . Is there one preferable RIVES, and how can it be
seen.
Thanks,
Henk

-- 
Henk Thijs
member F68 photography : http://www.f68.nl
webmaster : http://www.luca-antiek.nl