Why Physical Colour Sample Approval Matters

Custom colour production for this terracotta panel range is subject to technical evaluation, production conditions and physical sample approval. The sample is the practical project reference because a RAL code, screen image or print cannot by itself define how the approved panel should appear.

Why digital and physical colour references differ

The exact colour-production and surface-treatment method has not yet been supplied and must not be invented. What is confirmed is that custom production may be developed according to a requested RAL reference, subject to technical evaluation, sample approval and production conditions. A screen uses emitted light and a print depends on ink, paper and profile, so neither can serve as the final acceptance standard for the physical product.

Why lighting conditions change the outcome

Any physical surface can appear different as its texture, viewing angle and lighting change. A sample assessed indoors under artificial lighting may therefore read differently outdoors at the building site. Reviewing the physical sample under conditions representative of the project gives a sounder basis for approval than relying only on a studio photograph or digital rendering.

Scale changes perception too

Colour and texture that read one way on a small sample chip can present differently once assembled across a full façade at building scale, where repetition, joint lines and overall massing affect how the eye reads the colour. Where practical, reviewing a larger sample panel or a mock-up area — rather than a single small chip — gives a better indication of the finished appearance, particularly for projects with a high-visibility elevation.

Where this fits in the custom colour process

Sample approval sits between technical evaluation and final production confirmation in the custom RAL development process. Non-standard custom colours outside the main range have a 400 m² minimum order quantity. See colours and surfaces for the six standard colour names; project teams should still confirm availability, sample requirements and acceptance criteria for the selected family. The technical resources page identifies documentation that remains available on request.

Practical guidance for approving a sample

Where possible, review the sample outdoors, in daylight, and at the time of day most representative of how the finished façade will typically be viewed. Compare it against adjacent materials that will actually sit next to the panel on the building — window frames, other cladding, structural elements — rather than in isolation. Involve everyone with sign-off authority in a single review rather than sequential individual approvals, since colour perception is genuinely subjective and a single group review reduces the risk of late disagreement.

Common mistakes when reviewing samples

A frequent mistake is approving a colour based on a digital photograph of a sample sent by email, rather than the physical object itself — photography introduces its own colour-rendering variation on top of the differences already discussed between fired clay and digital display, effectively adding a second layer of inaccuracy. Another common mistake is a single reviewer approving a sample on behalf of a wider design or client team without that team seeing the physical sample themselves, which risks disagreement resurfacing after production has already begun. A third is comparing the sample against a printed material board rather than the actual adjacent materials specified for the building.

What to do if the sample doesn't match expectations

If a physical sample does not meet expectations, the appropriate response is to provide specific, comparative feedback — referencing the requested RAL number and describing the perceived difference — so a revised sample can be produced, rather than proceeding with an approval that isn't genuinely satisfactory. Since custom colour development already includes evaluation and sampling as standard steps, requesting a revised sample is a normal part of the process rather than an exceptional delay, though it should be factored into the project programme as discussed in the custom RAL development process.

Sample retention and future reference

Once a sample is approved, retaining it — rather than only keeping a record of the RAL number — gives the project a physical reference for checking delivered production against what was actually approved, and for any future phase or extension of the same building that may need to match the original colour. A retained sample is a more reliable long-term reference than a RAL number alone, precisely because of the fired-clay variation this article has described.

Who should be involved in the approval decision

Sample approval works best when it includes everyone with genuine sign-off authority on the project's material palette — typically the lead architect, and where relevant the client or their design representative and any planning or heritage authority with a stake in the façade appearance. Approving a sample without input from a party that will later raise an objection risks reopening a decision after production has started, which is a costlier point at which to discover disagreement than before the sample stage.

What the approval record should contain

Record the project, RAL request or standard colour name, panel family and format, sample identifier, review lighting or location, decision date, approver and any stated limitations. Photographs can support that record but should not replace the retained physical reference. If the sample is rejected, document the requested change without assuming which production method will be used to achieve it.

Moving forward with a sample request

Sample requests are handled as part of the custom colour development process through the project enquiry form — include the RAL reference and, where possible, the project location so the sample review can be planned around real site conditions.