By Stephanie Walker, Head of Technical at James Cropper
It’s easy to be mystified by colour management.
Every individual perceives colour slightly differently. The human eye has roughly 126 million photoreceptor cells, creating 126 million opportunities for variance. Amongst a whole host of biological and cognitive factors, there are also environmental factors to consider. For example, surrounding lighting conditions influence how we see colour.
This opens the door to fascinating quirks of colour like metamerism – a phenomenon where two colours appear identical under certain wavelengths of light, but very different under another wavelength. And then there are oddities like magenta, which has become a staple of printing thanks to the CMYK colour model even though it doesn’t exist as a spectral colour, and is simply the result of our brains combining two different wavelengths of red and blue light.
All of this is just the tip of the iceberg when it comes to mastering colour. How do you tame all these unpredictable, subjective elements, combining them into a single shade that perfectly matches a brand’s vision? How do you balance the interactions between pigments, dyes, and different substrates? And how do you ensure the final product looks as good under natural sunlight as it does under store lighting? It might seem like alchemy, but the truth is it’s a matter of expertise. And no one has more colour expertise than James Cropper.
In living colour
James Cropper’s history with colour goes back to the year 1856, when it became the first company in the world to produce coloured paper. Since that time 170 years ago, every new colour developed by James Cropper has begun its journey in the same place – the colour lab at James Cropper’s Burneside mill, a UNESCO World Heritage Site.
When a customer first approaches James Cropper with a colour matching project, initial discussions take place to identify the customer’s needs. This centres not just on the colour, but on the materials used and the end application. These are critical pieces of information, as they can fundamentally change the appearance of coloured pigments or dyes.
One of James Cropper’s most famous projects makes the perfect example of this point: the Royal British Legion’s paper poppies. These poppies must match distinct shades of red and green, but they also have to be resistant to colour bleed. As the poppies are traditionally worn on the outside of clothing during wet British Novembers, they also have to be resistant to rain.
However, not every paper product has the same requirements. A product made to be displayed in a window does not necessarily need to be strong or water-resistant, but it does need to be lightfast to prevent fading over time. A shopping bag or a retail box, on the other hand, needs to be structurally robust and resistant to rubbing.
Each of these uses comes with its own performance requirements, and meeting these requirements can influence the colour of the end product. This is because it determines whether dyes or pigments should be used – two types of colourants with very different applications.
A material difference
These differences stem from the unique chemical properties of pigments and dyes. Pigments are large, insoluble particles that are suspended in a binding solution that attaches to the surface of a material. This is as opposed to dyes, which are smaller, soluble particles that permeate into the substrate.
This key chemical difference gives both distinct benefits that make them well-suited to different applications. Pigments tend to be more lightfast, meaning they are ideal for museum-quality paper and archival materials for example. However, as the colour particles attach to the surface of the substrate, they are more likely to be pulled away by rubbing against other objects. Dyes, on the other hand, permeate fibre, meaning they are less likely to rub away, but more likely to bleed when wet.
These issues can be mitigated with a variety of different coatings and finishing techniques, each of which comes with its own effect on the colour of the final product.
And, of course, all of these factors have to be considered when developing a colour and weighed against the nature of the material itself. Virgin fibres straight from the tree provide a more uniform look, whereas recycled content, which is particularly popular in the print and packaging sectors today as a result of tightening environmental legislation, is much more variable. If the fibre has been dyed, coated, filled, or brightened, then this has to be accounted for during the colour matching process.
To return to the poppy as an illustrative example, the paper is made using a blend of virgin fibre and recycled material sourced from coffee cups. It is coloured using a blend of pigments and coated to ensure the final colour does not rub away when it comes into contact with clothing. The pigments used are carefully selected to account for this coating, ensuring the final red perfectly matches the poppy’s trademark vibrant hue after the coating is applied.
While this example illustrates just some of the challenges and variables involved in colour matching, in reality, virtually everything can affect the final colour result, ranging from water quality to temperature to the humidity on the day of production. However, if it can be made in a single sheet in the lab, then these conditions can be recreated and scaled up for full production.
This is why it’s important that the colour lab and the production machinery are both situated at the James Cropper mill in Burneside. Their co-location enables the company’s colour technicians to work closely with machine operators to make sure that every variable is accounted for. In some cases, the colourants can behave differently in the harsh environment of a machinery line compared to the lab environment, so additional tweaks may need to be made to ensure the final result matches the customers’ expectations.
Seeing colour in a new light
This speaks to perhaps the main benefit of James Cropper’s location. At a time when onshoring assets in the UK is strategically important to many companies, having a supplier with deep roots in the country is a huge advantage. It means customers and partners can visit the mill in person, experiencing the colour matching process for themselves.
Visitors can see the way the fibre pulp is mixed, coloured, and pressed, witnessing the profound impact different materials and lighting can have on the process. They can experience the whole journey, from pulp to coloured paper, at the UK’s only remaining coloured paper mill, getting a feel for the attributes of their chosen material in a variety of conditions. And they can quiz James Cropper’s team of colour experts, going back and forth on colour prototypes in a constructive creative partnership that enables the customer to pinpoint the exact shade they have in their mind.
In a process where so much is subjective, this is an invaluable benefit for James Cropper customers. Colour is an everyday miracle that is easy to take for granted. Mastering colour requires the management of a staggering number of variables, combined with cutting-edge technology, psychology, and ocular biology. The results of this combination are 170 years in the making, and they need to be seen to be believed.
Now the doors to the James Cropper colour lab are open, every customer is invited to see colour in a new light – literally. It’s a place where centuries of craftsmanship meet the latest advances in science, and where subjective perception is transformed into objective precision.
For brands, designers, and manufacturers, this isn’t just about matching a swatch; it’s about unlocking the emotional power of colour and ensuring it performs exactly as intended in the real world. From heritage projects steeped in tradition to cutting-edge innovations pushing the boundaries of sustainable materials, James Cropper remains the partner of choice for those who refuse to compromise on vibrancy, accuracy, or impact.
Because when colour matters this much, nothing less than perfection will do.
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