Cross-Processing

Cross-processing means deliberately developing film in the "wrong" chemistry — typically running slide film through C-41 colour negative chemicals, or colour negative film through E-6 slide chemicals. The results are unpredictable, often garish, and distinctly analogue in a way that's nearly impossible to replicate digitally.

What is Cross-Processing?

Standard processing matches film to chemistry:

• Colour negative film → C-41 process
• Colour slide film → E-6 process

Cross-processing breaks this rule:

• E-6 slide film → C-41 chemistry = "Cross-processed slides" (most common)
• C-41 negative film → E-6 chemistry = "Cross-processed negatives" (less common)

Each combination produces different, characteristic results.

E-6 Film in C-41 (The Classic Cross-Process)

This is the "xpro" look that defined 90s and 2000s alternative photography and fashion editorials.

Characteristics

• Increased contrast — Often dramatically so
• Shifted colours — Blues go cyan, reds go orange, greens go yellow
• Colour casts — Varies by film but often green/cyan shadows, yellow/red highlights
• Pronounced grain — Especially in shadows
• Surreal, punchy aesthetic — Nothing looks natural

Why It Happens

Slide film is designed to be viewed directly — the dyes are optimised for projection. When processed in C-41:

• The colour coupler chemistry differs between processes
• Dye layers react unpredictably to C-41 chemistry
• The film's orange mask (absent in slides) means scanning works differently
• Contrast characteristics designed for reversal create punchy negatives

C-41 Film in E-6 (Less Common)

Processing colour negative film in E-6 chemistry produces different results:

Characteristics

• Low contrast — Often flat, pastel appearance
• Muted colours — Desaturated, dreamy look
• Reversed tones — Creates a positive image (slide) from negative film
• Orange cast — The film's orange mask affects the final image
• Soft, vintage aesthetic — Less aggressive than E-6 in C-41

This combination is less popular because results are more subtle and the process requires E-6 chemistry (less common than C-41).

Best Films for Cross-Processing

E-6 Films (for C-41 Processing)

Excellent results:

• Kodak Ektachrome E100 — Strong greens/cyans, good contrast
• Fuji Provia 100F — Green/cyan cast, punchy colours (discontinued but still available)
• Fuji Velvia 50/100 — Extreme saturation becomes even more extreme

Interesting results:

• Lomography X-Pro Chrome — Designed for cross-processing
• CineStill 50D — Technically ECN-2 but can be cross-processed

C-41 Films (for E-6 Processing)

Worth trying:

• Kodak Portra 400 — Produces soft, pastel positives
• Kodak Gold — Warm, vintage look
• Fuji Superia — Cool tones, dreamy aesthetic

The Cross-Processing Process

E-6 Film in C-41 (Standard Method)

The process is identical to normal C-41 development:

No special adjustments are needed. The "cross" effect comes entirely from the film/chemistry mismatch.

Time Adjustments

Some photographers adjust development time for cross-processing:

C-41 Film in E-6

This requires E-6 chemistry and follows the standard E-6 process:

Scanning Cross-Processed Film

E-6 in C-41 (Negative)

• Scan as a colour negative
• The scanner's orange mask correction may produce odd results — try with and without
• Often benefits from manual colour correction
• Embrace the unusual colour palette rather than fighting it

C-41 in E-6 (Positive)

• Scan as a positive/slide
• The orange mask creates a colour cast that needs correction
• Manual white balance adjustment usually required
• Results are inherently low-contrast — may need curve adjustment

Predicting Colour Shifts

While cross-processing is somewhat unpredictable, certain patterns emerge:

E-6 in C-41 Tendencies

Exposure Effects

• Overexposed slides in C-41 — More saturated, extreme colours, lighter overall
• Underexposed slides in C-41 — Muddy shadows, blocked-up look, green cast in darks
• "Correct" exposure — Punchy contrast, colours as described above

Creative Applications

Cross-processing suits certain subjects better than others:

Works well:

• Fashion and editorial work
• Street photography with graphic elements
• Portraits (if you embrace unusual skin tones)
• Urban landscapes and architecture
• Intentionally surreal/dreamlike imagery

Challenging:

• Natural, accurate colour reproduction (obviously)
• Subtle tonal work
• Professional product photography
• Anything requiring consistency

Lab Cross-Processing

Many labs offer cross-processing as a service:

How to Request

• Clearly mark your order as "Cross-process" or "Xpro"
• Specify "E-6 film in C-41" or vice versa
• Some labs refuse — call ahead if unsure
• Expect to pay standard C-41 or E-6 rates

Home vs Lab

Home advantages:

• Full control over process
• Can experiment with times
• No explaining to confused lab staff

Lab advantages:

• Consistent, calibrated chemistry
• No equipment needed
• Convenient for occasional experiments

Historical Context

Cross-processing became popular in the 1990s through:

• Fashion photography — Juergen Teller, Corinne Day, early Terry Richardson
• Album covers — The distinctive aesthetic appeared across indie and alternative music
• Lomography movement — Embraced unpredictability and experimentation
• Magazine editorials — The Face, i-D, and other style publications

The look fell out of favour as digital processing could simulate similar effects, but it's seeing renewed interest as photographers seek authentically analogue aesthetics.

Managing Expectations

Cross-processing is inherently experimental:

• Batch variation — Even the same film stock varies between batches
• Storage effects — Old or poorly stored film shifts unpredictably
• No "correct" result — What you get is what you get
• Embrace accidents — The unpredictability is the point

Getting Started

For your first cross-process experiment:

Cross-processing rewards experimentation. The unexpected results are features, not bugs — and the distinct aesthetic is impossible to authentically recreate any other way.