[RStorment]

I seem to disagree... I think they match pretty well, actually. I built a bookshelf using a birch ply, and faced it with poplar, simply because it was cheap. They both have a pretty smooth grain pattern, though I would definitely avoid a piece with green streaks. I used water-based stain and shellac and they seem to match up fairly well, although the poplar we have down here in Mississippi is quite soft. Next time I would think about using an oil to harden the wood.