Yupo is a slick watercolor paper that's flexible, smooth, and brilliantly white. Because the surface is so smooth, paint just sits up on stop and doesn't get absorbed - so the oil colors stay transparent and jewel-like. The surface also prevents me from getting very detailed with the image. All in all, it's a huge amount of fun to work with! This piece is mounted on cradled hardboard without a frame and looks wonderfully contemporary.