These cartridges stand up to a steady diet of 1200 dpi at 12, 16, 18, or 24 ppm without missing a dot. They print on everything from bond paper & card stock to transparencies & labels. Gray scale transitions are super smooth to ensure the best possible print quality. Return/ Prebate cartridges are sold at a discounted price vs. the price of regular cartridges in exchange for the customer's agreement to use the cartridge only once & return the cartridge to Lexmark for recycling once it's empty. All toner boxes ship with prepaid postage labels for customers to return their empty cartridges for recycling.