RISO paper does not require proprietary branded sheets, meaning users can utilize standard uncoated, porous paper stock (such as offset paper, cardstock, or recycled paper) priced similarly to regular office or art paper (typically $5 to $20 USD per ream). Because RISO ink relies entirely on physical absorption rather than thermal heat-fusing, avoiding glossy or coated papers is essential to prevent smudging and drying failures.