Sirio cardstock is a high-quality cardstock produced in Italy and shipped straight to your doorstep. At 12x12 Cardstock we work hard to bring you the best cardstock options, and Sirio is known worldwide for their rich shades of high-quality cardstock in unique finishes. We start off our Sirio cardstock collection with Sirio Ultra Black Cardstock. This is the best black cardstock and the deepest black cardstock on the market! A rich, deep, dense, black cardstock that has color all the way through, so you won't get white edges when torn or cut. The heavier weight gives added stability to projects and the deep, intense black makes all the other colors pop against it.