Same experience here. Clearprint Vellum gives good Dmax without any oxalic acid soak.
Originally Posted by clay
One problem I have had with Rising Stonhenge is that the oxalic acid soak appears to remove the surface sizing, which opens up the texture and results in a very grainy kind of image in the uppper highlights. I have also seen this with a few other papers. The oxalic soak is good in that it increases Dmax, but the resultant grainy look is quite unpleasant.
What I would ask, and Clay most likely knows as much about this as anyone I could ask, is which papers work well with the oxalic acid soak and which don't.