Same logo, different colours? How to make the print on a display wall, roll-up and flag consistent

Ordering a complete exhibition kit made up of a textile wall, a roll-up and an advertising flag at the same time is a classic branding step for any company planning to exhibit at trade fairs or conferences. Unfortunately, when the finished displays are unpacked, many business owners are unpleasantly surprised: although identical CMYK values were entered in all the files, the company navy looks purplish on the flag, the roll-up looks dull and the textile wall shows a rich cobalt. This is not necessarily a manufacturing defect or a print shop mistake – it comes from the laws of physics, optics and dye chemistry. In this expert guide we present a complete procedure for checking colour consistency across a whole promotional kit, so that you can minimise the differences and get a harmonious look on every material.

Table of contents:

1. Why does the same logo look different on different displays?
2. The influence of the substrate: base white, absorbency and texture
3. Technology differences: sublimation, UV and eco-solvent
4. Comparing displays: properties of advertising substrates
5. A procedure for checking the colour consistency of a whole kit
6. Step 1: Agree a physical colour standard and standardise the files
7. Step 2: A test print of the display wall and material samples
8. Step 3: Visual check and avoiding metamerism
9. The limits of on-screen previews – why a monitor is not enough
10. Frequently asked questions (FAQ)

Why does the same logo look different on different displays?

The basic mistake made when planning promotional materials is assuming that entering an identical CMYK colour code, or even a Pantone number, guarantees an identical look on every material. In practice, graphic designs for display systems need a completely different technical approach from classic commercial printing on coated paper. Just put the three basic elements of a trade fair identity side by side – a textile wall, a roll-up and an outdoor flag – and you will see that each uses a completely different substrate, a different type of ink and a very different method of fixing the graphic.

From the point of view of spectrophotometry, colour is not a fixed property of an object, but a visual impression caused by light reflected from or passing through a surface. When the same light falls on the dense polyester fabric of a wall, the smooth polypropylene film of a roll-up and the airy knitted fabric of a flag, it is reflected at different angles and absorbed to different degrees. That is why colour differences in print are visible even to people with no printing background, and the brand's visual identity looks inconsistent.

The influence of the substrate: base white, absorbency and texture

A print substrate is not a neutral, perfectly transparent background. Every material has its own base white with its own colour temperature, which directly determines the final shade of the transparent inks applied to it. Polyester fabrics used for display walls often have a cool, slightly bluish white, which makes cool tones vivid but can cool down warm reds and yellows. Blockout or no-curl materials used in high-quality roll-up cassettes, on the other hand, may have a slightly yellowish base or a grey light-blocking core that reduces the brightness of colours.

Surface structure is another factor. The smooth material of a roll-up reflects light evenly, almost like a mirror, which increases optical contrast and the depth of black. A woven fabric creates micro-shadows and scatters light. Flag knit is an open material with a very low weight, so much of the light simply passes through it. As a result, brand colours on different materials show a noticeable drop in saturation unless they are corrected when the machine is calibrated.

Technology differences: sublimation, UV and eco-solvent

Consistency is harder to achieve because an exhibition kit is almost always produced with at least two different large-format printing technologies:

• Dye-sublimation printing (walls and flags): sublimation dyes penetrate the polyester fibres under the high temperature and pressure of a calender. The dye molecules become part of the fabric. Colours are extremely vivid and resistant to creasing and washing, but the gas migration process can slightly enlarge the halftone dot, affecting optical density.
• UV or eco-solvent/latex printing (roll-ups): for roll-ups, the ink cures on the surface of the substrate (UV curing) or bonds chemically with the top layer of the banner or synthetic material. The ink forms a physical coating on top, which gives precise, sharp edges to solid areas but a completely different level of gloss than matt polyester fabric.

Each of these technologies has its own colour space, called a gamut. The gamut of UV printing on a rigid substrate differs from that of sublimation on stretchy polyester. As a result, the same colour values in a PDF file are interpreted differently by the raster image processor (RIP) unless centralised colour management based on dedicated ICC profiles is used.

Comparing displays: properties of advertising substrates

To see how difficult it is for a print operator to make a trade fair kit consistent, look at the key technical parameters of the materials in the table below:

A procedure for checking the colour consistency of a whole kit

Many customers simply send one graphic file to different suppliers or choose express printing without any extra checks. Standard guides only explain how to export a graphic to PDF or TIFF with bleed and the right resolution. That is not enough when the goal is a perfect corporate image. Below is our three-step quality control procedure, which replaces passive waiting with active standardisation of the whole exhibition set.

Making colours consistent across different media does not mean sending the same file to three machines, but deliberately adjusting the colour curves for each substrate so that the human eye sees them as identical.

Step 1: Agree a physical colour standard and standardise the files

The starting point must be a physical reference. Never approve colours based on how a design looks on an office monitor or a phone. The industry standard is the Pantone Matching System (PMS), in particular the Pantone Formula Guide Solid Coated and Solid Uncoated.

When preparing integrated designs for different media, the designer should not simply convert Pantone libraries to an averaged Fogra39 CMYK profile. Instead, the base colour should be defined as a named spot colour. This allows the print shop's advanced RIP software to read the designer's intention and match the machine's ink recipe directly to the LAB value of the chosen Pantone number.

Step 2: A test print of the display wall and material samples

The most critical stage is the technical test. Many customers skip it for fear of longer lead times, which is a big mistake with multi-module stands. A classic certified digital proof on photo paper tells you nothing about how the dye will behave on stretchy textile polyester or on flag material.

The solution is to order test strips (strike-offs) on the target media. With a test print of the display wall, you get a piece of fabric printed with the key element of your identity – usually the logo on a solid brand background – surrounded by a mini palette of colours shifted a few per cent towards magenta, cyan or yellow. The same test is done at the same time on the roll-up material and the flag knit. This lets the machine operator compare physical samples and fine-tune the colour curves before the main run starts.

Step 3: Visual check and avoiding metamerism

Once the samples come off the machines, it is time for the final assessment. This is where wrong conclusions are most often drawn because of a phenomenon called metamerism: two materials with different dye chemistry and surface structure look perfectly matched in one type of light, but clearly different in another.

For a reliable assessment, put the wall, roll-up and flag samples directly next to each other at the same angle and check them under two lighting conditions:

• Standardised D50/D65 light: professional light booths that simulate natural daylight with a colour temperature of about 5000 K to 6500 K. This allows an objective assessment of the purity of the shade.
• The real light of the venue: exhibition halls are usually lit with metal halide lamps or industrial LED fittings at 3000 K to 4000 K. Checking the samples under warm artificial light ensures that the company navy will not turn brownish and greys will not turn greenish.

The limits of on-screen previews – why a monitor is not enough

Many marketers ask why approving a file on a calibrated graphics monitor does not solve the problem of colour differences. The answer lies in the fundamental difference between additive RGB synthesis (light emitted by pixels) and subtractive CMYK synthesis (light absorbed by pigments). A monitor emits light directly towards the viewer's eye, so colours always look cleaner, brighter and more contrasting than on any non-illuminated material.

What is more, no monitor can fully simulate the physical properties of a material, such as how much light passes through a flag waving in the hall or how light refracts on polyester microfibres. If you want perfect reproduction of your visual identity and a stress-free production process, leave file preparation to professionals and order dedicated design services, in which prepress specialists make the necessary halftone and colour compensations for specific machines.

Frequently asked questions (FAQ)

Does giving a Pantone code completely remove colour differences between a roll-up and a wall?

A Pantone code is the best starting point, but on its own it does not remove the physical limitations of the substrates. A Pantone guide defines the target colour as a mixed ink on a specific paper. Because large-format printing simulates these colours with a set of CMYK inks (often extended with extra colours such as light cyan, light magenta or orange), how closely they are reproduced depends on the machine's gamut and the absorbency of the material. A Pantone code does, however, allow the print shop to measure the colour deviation (Delta E) objectively and correct the machine profiles.

Why does the graphic on an advertising flag look lighter than on a wall made of the same fabric?

Flags are not made of the same fabric as walls. Flags use an airy, very thin polyester knit of about 110 g/m², designed to move freely in the wind and let the dye show through almost completely on the reverse. As a result, the flag knit lets a huge amount of ambient light through its structure, which the human eye sees as lighter and less saturated compared with the dense, light-blocking fabric of a textile wall.

When is it worth ordering a test print of a display wall?

A test print (strike-off) is strongly recommended when introducing a new visual identity, for orders with a large budget and when the logo contains critical colours that are difficult to reproduce in CMYK. These include deep navy shades, turquoises, saturated oranges, corporate purples and neutral cool greys, which are the most prone to colour casts depending on the substrate.

What is Delta E and why does it matter when accepting display systems?

Delta E is a mathematical standard developed by the International Commission on Illumination (CIE) that measures the distance between two colours in the LAB colour space. A Delta E below 1.0 is usually invisible to the human eye. Values between 1.0 and 2.0 are only noticeable to a trained observer when samples are placed side by side. In large-format printing on different substrates (combining textiles and plastics), the industry tolerance is usually a Delta E of 2.0 to 3.5.

Are you planning to exhibit at trade fairs and want to be sure your stand will look perfectly consistent in colour? Contact our technical advisers using the RETIO contact form – we will help you choose the right displays, check your graphic files and prepare test prints tailored to your needs.