Probably sharpest will be the one with the less weave in it, high white gloss, and flatter surface.
I made a couple of canvas prints today using Premier Arts Canvas and Inkpress Glossy Canvas. The Inkpress is the sharpest, but the weave is tighter (smaller) than the Premier and not as deep either. The Inkpress has what I would call a heavy gesso applied to the surface verses the Premier with more canvas-like appearance. Premier is heavier too than the Inkpress.
Personally, I like the Premier since I seem to fetch the most competition awards using it. Has nice bright specular highlights due to the depth of the heavy canvas too, somewhat like dew drops. Coupled with their Art Spray Lacquer and it really is nice stuff. Takes gels well too if you are into that print painting stuff.
Not of fan of BC due to ink bleed on their Silverada Metallic Canvas, aside from odd curl to the edges and bad head strikes occurring in the printer and knocking it askew in the rollers.
Canson had a very nice black as I recall in their newest HD Art Canvas, but don't recall the sharpness as the black was surprisingly black like it had a lacquer sprayed on it. Might be my next roll purchase.
Really is a personal preference at times.
SG