What is skip-bleach processing?

Internet Filmmakers' FAQ

Skip-bleach Processing refers to a technique whereby artistic ends are achieved through a kind of "incorrect" processing of colour film. In all film stocks, it's silver that reacts to light. In colour film stocks, when the silver reacts to light, it causes a colour dye coupler to form colour dye next to it. In developing, the silver itself (which is black after exposure and developing) is washed - or "bleached" - out. If you leave the silver in the print "skipping" or "bypassing" the bleach step - the image will have black silver sort of contaminating all the colours. The contrast increases, the blacks get very dense, and the colours get darker and more de-saturated.

Spielberg's Saving Private Ryan made use of a variation of skip-beach processing called ENR, created by Technicolor Labs. In this case they run the print through a second black & white developer to develop in the silver permanently (with a skip-bleach print, you could, in theory, later still wash out the silver.) By varying the strength of the developer, they can control how much silver gets left in - while the skip-bleach process leaves ALL the silver in. So the ENR process can be as subtle or as strong as you like. For example, the prints for Evita used a 30% ENR, the prints for The Game used a 60% ENR, and I think that Saving Private Ryan used a 90% ENR. Deluxe Labs also has a ENR process now called ACE. Their skip-bleach process is called CCE.

This answer is based on a response by David Mullen to a similar question on RAMP.

Answer by Benjamin Craig  |  Last updated 19-Nov-2004


Older Comments

shadowcaster@angelfire.com  |  19-Nov-2004
Most labs will perform "skip-bleach" or "bleach-bypass", but tend to prefer to do so on larger (feature-length) projects only, due to the equipment reconfiguration required. There is usually an additional charge for bleach-bypass, as they usually sell the recovered silver back to the film manufacturers. ENR, on the other hand, is a proprietary procedure unique to Technicolor. No-one else will do it. Keep in mind that if your project is for broadcast, you can generate the same feel in post-production.