Finding Mono – Paul Roark – Carbon Sensei

After getting comfortable with the ideology of Cone and Harrington’s world of carbon purity and control, but frustrated by its inaccessibility to a lowly hobbyist in North East Scotland, I began to look around for a way forward. I wanted Multi‑shade carbon, engineered neutrality, tonal architecture – it all made sense. The architecture was all there, but remained just out of reach.

Thats when I discovered a mine of knowledge, shared by the very generous fine-art photographer, Paul Roark. https://www.paulroark.com/

Paul came not from the commercial side of things, but from the early digital photography community, the forums, the mailing lists, the experimental corners where photographers shared discoveries the way darkroom printers once shared formulas. Roark was a fine‑art photographer first, an engineer by temperament, and a documentarian by instinct. He approached inkjet printing the way a darkroom printer approaches chemistry: with curiosity, discipline, and a refusal to accept mystery where measurement would do.

And what he wanted was simple: pure carbon – predictable tone – a workflow anyone could afford.

John Cone’s Piezography was beautiful, but expensive and proprietary.
Epson’s own inks were colour‑centric and unstable in tone.
Third‑party colour inks from Canon or HP were irrelevant.

So Roark did something more aligned with my personal ethos than I am comfortable to admit – he rolled up his sleeves and started testing.

MIS, a third‑party ink supplier, happened to make a carbon‑rich black called Eboni, which was cheap, stable, and consistent. From that single pigment, Paul built Eboni‑4 and Eboni‑6: Two dilution ladders designed not as commercial products, but as principles:

• keep the pigment pure
• keep the dilutions simple
• keep the workflow transparent
• keep the cost low
• keep the knowledge open

Where Cone offered a finished commercial world – which absolutely has its place – Roark offered a set of tools and said, “Here: build your own.”

And crucially, Roark embraced QTR not as a proprietary engine, but as a public utility. QTR gave him exactly what he needed:

• per‑channel control
• predictable curves
• a darkroom‑like mindset
• a platform for experimentation

Roark didn’t need a branded system. He needed a framework, and so he created one – openly, methodically, and with a generosity that still feels rare in this field. His PDFs, dilution charts, density curves, and QTR files became a kind of open‑source library for anyone who wanted to understand monochrome printing from first principles.

He wasn’t selling inks – He wasn’t selling curves – He wasn’t selling anything:

He was sharing knowledge – and knowledge is something I can use!

Eboni‑4 and Eboni‑6

The open‑source ladders that made carbon printing accessible

Roark’s genius wasn’t that he invented a new pigment – he didn’t.
His genius was that he looked at the printers ordinary photographers actually owned and asked a simple question:

What is the best monochrome system I can build with the channels available?

That question produced Eboni‑4 and Eboni‑6, two dilution ladders that became the backbone of open‑source carbon printing for nearly two decades.

Eboni‑4 was designed for the printers most people had in the early 2000s: These were 4‑channel or 6‑channel printers, but crucially, they only had four channels that could be repurposed cleanly for monochrome without wasting expensive colour positions.

Roark’s logic was brutally practical:

• Four usable channels → four shades
• One pigment → simple dilutions
• QTR → per‑channel control

The dilution ladder was:

• 100% Eboni
• 50%
• 25%
• 12.5%

A one‑stop geometric progression, clean and mathematically elegant. It was the best compromise possible with four channels.

Eboni‑4 prints were:

• carbon‑pure
• stable
• affordable
• surprisingly smooth for their era

But they had limitations:

• visible steps in the highlights
• limited tonal subtlety
• a shorter smooth midtone ramp
• occasional grain in very light areas

Still, for a four‑shade system, it was astonishingly good – and it opened the door for thousands of photographers who could never afford Piezography.

When Epson released printers with six usable channels (C, M, Y, K, LC, LM), Roark immediately saw the opportunity.

The Epson 1280, 1290, R800, R1800, R2400, and similar models suddenly offered enough channels to build a smoother tonal ladder.

Eboni‑6 was born. https://www.paulroark.com/BW-Info/Eboni-6.pdf

The dilutions were not geometric, but perceptually optimised though testing to give greater tone resolution in the highlights.

• K = Eboni (The standard MIS Associates carbon matte black ink)
• C = EB6C (30% Eboni, similar in density to the standard MIS UT dark gray density)
• M = EB6M (18% Eboni, similar in density to standard LK)
• LC = EB6LC (9% Eboni, similar in density to the MIS UT Light Carbon density)
• LM = EB6LM (6% Eboni, similar in density to standard LLK)
• Y = EB6Y (2% Eboni, a very light “LLLK”)

This gave:

• smoother highlights
• better midtone control
• more subtle transitions
• a longer tonal scale

Roark wasn’t trying to build the perfect system. He was trying to build the best system he could with the hardware people actually owned – and he succeeded.