I just bought a canon pixma pro-100 printer to print greeting cards. The printer works beautifully on Canon glossy photo paper, but it is terrible on 80lb cardstock--which is unfortunately what I use for my greeting cards. The output is kind of grainy instead of rich and smooth. The media type setting that works best for my cardstock is "plain paper" but it's still not very good. How might I go about troubleshooting this? Or is this printer fundamentally unsuited to my needs/cardstock?