Breathing Color used to sell 30MS Decor Art Paper a while ago, but it was discontinued. It was a 300gsm smooth bright white paper with a matte finish. It seemed just like Optica One, except it was alpha cellulose instead of 100% cotton. It had OBA's, and wasn't archival certified.
They don't have a new product to fill that area, for a really inexpensive smooth art paper, that was decent except for not being archival. They have 28MT which is priced similarly, but that's a thinner (220gsm) and textured paper. Sticking with smooth is Optica One or Pura Smooth, both of which are much more expensive (but still a great price for what they are.)
Any recommendations? I know there's cheap paper rolls, but what I loved about 30MS is that it wasn't "junk", it was much better than something like a doubleweight paper of inexpensive price. It was something decent for clients more concerned about price than longevity. It was still thick and still had a nice color gamut (near that of Optica One, but I never had custom profiled so can't check in ColorThink Pro).
EDITS: MHMG corrected me that Optica One wasn't OBA free, so I fixed that, and Mark Segal's right that I shouldn't be calling what I'm looking for fine art paper, that must be why Breathing Color called it decor art paper, so I fixed my title and removed references to "fine art" paper.