MRH42A: Vortex Plus Versatile Black Ink Cartridge for Address Printing - Compare to HP C8842A Versatile Black and Collins Complete. Vortex Plus MRH42A is an ink cartridge that works very well on a variety of stock, porous & non-porous. It provides excellent quality and density and is designed for high volume & high speed mail systems. This ink is quick drying & the drying process is enhanced with the use of a heater/dryer.