The Hudson's curved spine rests beautifully in the palm of your hand, while the built-in photo sleeves allow for easy loading. The Hudson 3-up is designed to hold 300 4" x 6" prints and the Hudson 2-up will hold 200. For the covers, we used our fine book cloth to coordinate with the rest of the Kolo collection. The perfect way to quickly, but elegantly organize your photos without using corners or tapes. Also available in bonded leather. Non-refillable.