I did these custom letterpress business cards awhile ago. These are on our standard paper, a luxe 110lb 100% cotton (tree free) cardstock. For these cards, our client chose to go with fluorescent ink, which is a special order ink here at Joie Studio. The results are gorgeous.
I get asked a lot what the difference is between bright white or pearl white. Colin's letterpress business cards are in bright white. Valery's is pearl white - a creamier natural white. Colin's cards are printed on super luxe 220lb cardstock, while Valery's are on our standard luxe 110lb cardstock. You can see how much thicker Colin's is in the pic below.