The Kodak Professional Portra family of films was originally launched in 1998. Since then, Kodak has made many advances in color negative film technology. The films introduced at Photokina 2006, the Kodak Professional Portra 160 NC and VC, and the 400 NC and VC films, have been reformulated to improve performance. This paper will describe the new components and their features. These include emulsion improvements: optimized T-Grain technology, antenna dye sensitization, and improved spectral sensitivity. Chemical improvements are also described: Advanced development accelerators, a new high-efficiency masking coupler, and improved DIR couplers.
Daniel Kennelly, "New KODAK PROFESSIONAL PORTRA Films: Re-Engineered for Improved Performance" in Proc. Int'l Symp.on Technologies for Digital Photo Fulfillment, 2007, pp 9 - 9, https://doi.org/10.2352/ISSN.2169-4672.2007.1.0.9