---
title: "What is the difference between C41, E6, B&W, and ECN-2 processing? Which does my film need? | Neo Analog Lab"
url: https://shop.neoanaloglab.com/en/news/faq-c41-e6-bw
language: en
description: "C41 = color negative, E6 = reversal (slide), B&W = black-and-white negative, ECN-2 = cinema film. Check the film box or cassette markings."
---

# What is the difference between C41, E6, B&W, and ECN-2 processing? Which does my film need?

C41 = color negative, E6 = reversal (slide), B&W = black-and-white negative, ECN-2 = cinema film. Check the film box or cassette markings.

faq Neo Analog Lab Published July 9, 2026 Updated July 11, 2026

faq developing film-basics

**C41**: the standard process for color negative film - Kodak Gold, Portra, Fujifilm color negatives.

**E6**: for reversal (slide) film, which develops into a positive you can view directly on a light table - Ektachrome, Provia, Velvia.

**B&W**: black-and-white negative development - HP5 Plus, Tri-X, Delta, ACROS. B&W reversal is a separate, special process.

**ECN-2**: for cinema color negative stocks like Kodak VISION3 (500T, 250D). The chemistry differs from C41 and the remjet backing must be removed.

When in doubt, check the box or cassette for "Process C-41" / "E-6" markings - or just write the film name in the order notes and we will identify it for you.

## Sources

- [Kodak VISION3 500T technical data sheet (Process ECN-2, rem-jet backing)](https://www.kodak.com/content/products-brochures/Film/VISION3_5219_7219_Technical-data.pdf)
- [ILFORD's official black & white reversal processing guide](https://www.ilfordphoto.com/reversal-processing/)
- [Kodak EKTACHROME E100 product page (E-6 process)](https://www.kodak.com/en/still-film/product/professional/ektachrome-e100-film/)

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