Bulk Ink for inkjet printers. We offer a variety of bulk ink sizes to choose from for your inkjet printer / cartridge. DuraFirm Technology ink (all-brand inkjet ink) is available in 60ml, 250ml, and 1 gallon bulk ink sizes. Our ink is all-brand, which means it will work on ANY inkjet cartridge. Whats more, this ink is engineered and manufactured in the USA and is the highest quality refill ink we have found. Our bulk ink offers you the convenience of being able to refill ANY inkjet cartridge without compromising print quality. Bulk Ink is intended for repeat refill customers, wholesale customers, and refill / remanufacturing businesses. Bulk Ink is the way to go if you already know how to refill and are looking to save even more on your print jobs, especially if you do a lot of printing. Please choose from the following bulk ink categories: