This Cyanotype Paper - 8 x 10" (100 Sheets) from Blue Sunprints comes pre-treated and pre-washed. That means you can make these distinctive blue prints with ease. Pick out your desired objects or negatives and add the sun! After your prints are exposed, rinse and dry them. This 90 lb watercolor paper is both substantial and archival, providing you with images that will last for years to come.