A pallet delivery that shares one SKU can still carry more than one shade lot, and the buyer holding both cartons has to decide whether that difference is a paperwork detail or a reason to stop and check the material before it goes on the wall or floor. The SKU tells the crew what product they have; it does not by itself tell them whether every carton in the stack can sit in the same visual field without a visible break.
Confirm the SKU and Supplier Code Legend
A SKU identifies a product, not a specific production run of that product. Manufacturers separate these fields deliberately because a single product design can be produced across multiple firings, and each firing carries its own shade, caliber, batch, and quality identifiers even though the product description and SKU stay fixed. RAKO’s technical catalogue documents this directly: batches of the same product can differ in shade and dimensions, and the manufacturer identifies those differences at the package and pallet level rather than folding them into the product code. Villeroy & Boch’s technical guidance treats product identity and nuance or caliber identity as separate fields for the same reason — one code answers “what product is this,” the other answers “which run did it come from and how does it compare to other runs.”
For the project buyer, this means the SKU match confirmed at receiving is not the check that resolves a mixed-lot question. The carton and pallet markings carry the shade code, the caliber code, and often a batch or quality grade, and these can differ between two cartons that pass as the identical SKU on a packing list. Where the supplier’s legend is available and every carton is marked against it, the buyer can trace exactly which lots are present in the stock on hand. Where the legend is missing, illegible, or inconsistent between cartons, the buyer has no way to know whether “same SKU” also means “same shade lot” until that legend is obtained and applied.
This is also the point where the information a buyer supplies about the stock in hand becomes useful to a supplier review. When VITAGRES or another supplier is asked to confirm whether replacement or additional stock matches material already on site, the codes read off the cartons — not just the SKU — are what let that comparison happen. A product page such as the one for a specific porcelain tile identifies the product; it does not substitute for the lot-level codes that distinguish one production run of that product from another. The buyer who wants a supplier to confirm a match needs to bring both.
Map Each Shade Lot to the Intended Visual Area
Knowing that two lots differ is only useful once it is connected to where each lot is going. The same shade or caliber variation that is irrelevant in one layout can be a visible defect in another, because the consequence of variation depends entirely on how continuous the intended visual field is and whether the design already expects uniformity or variation.
Villeroy & Boch’s guidance draws this distinction directly: different nuances should not be combined where the product is intended to produce an even visual effect, while some ranges are designed with intentional variation built in. This means the same lot difference that would be disqualifying for one product line can be exactly what a different, deliberately varied range is supposed to deliver. The judgment does not sit in the lot codes alone — it sits in the gap between what the lot codes show and what the specified visual intent for that product actually calls for.
This is why mapping has to happen at the level of the visual area, not the level of the stock pile. A shade lot that will only ever appear in a small, visually isolated space carries a different consequence than the same lot destined for a single continuous floor or a wall elevation viewed as one plane. Where an area schedule already assigns quantities to rooms, elevations, or runs, each lot in stock needs to be checked against that schedule before installation, not after. Where no such schedule exists yet, the mixed-lot condition itself is the reason to build one, because without it there is no basis for deciding which lot goes where or whether a transition between lots needs to be planned rather than left to chance.
| Verification point | Evidence to compare | Proceed only if | Otherwise |
|---|---|---|---|
| Product identity | SKU, description and quality identifier | The intended product is the same | Hold and correct the identity |
| Shade and caliber identity | Supplier legend plus carton and pallet codes | Differences are understood and addressed by the project decision | Segregate pending review |
| Visual-field allocation | Area schedule and layout boundaries | Each lot has a deliberate area or transition | Replan allocation |
| Physical appearance | Controlled side-by-side review tied to lot IDs | The authorized reviewer records the bounded decision | Request replacement or hold |
| Remaining requirements | Specification and technical evidence | No open item is being waived by the visual decision | Keep those items open |
The matrix above organizes this comparison, but the judgment behind it is that a lot difference is not evaluated in isolation — it is evaluated against the specific area it is assigned to, and the same physical variation can pass in one assignment and fail in another.
Decide When Physical Side-by-Side Review Is Needed
Codes establish that a difference exists; they do not establish what that difference looks like once tiles are laid side by side under real lighting. Both RAKO and Villeroy & Boch recommend reviewing contents from multiple boxes under their own product guidance, which reflects a general limit of code-based verification: a shade or caliber code communicates that two lots were produced differently, but the visual size of that difference — and whether it reads as acceptable in the finished surface — is a judgment that codes alone cannot make.
Physical review becomes the necessary next step under a specific set of conditions rather than as a routine check on every delivery. It is needed where the shade codes on hand differ, because that is the direct trigger the code system exists to flag. It is needed where the installation area is a continuous visual field, because that is where a shade break is visible rather than absorbed by breaks in sightline. It is needed where the sample originally approved for the project does not represent both lots now in stock, because an approval based on one lot cannot be extended to cover a lot it never included. And it is needed where the code legend itself is unclear, since an ambiguous code cannot be trusted to describe the material without a physical check to confirm what it means.
Where none of these conditions hold — codes match, the area is not a continuous field, the approved sample already covers the lots present, and the legend is clear — a physical side-by-side review adds little beyond what the paperwork already shows. Where any one of them holds, the review is what turns a code-level flag into an actual project decision.
Setting up that review requires the same structure regardless of which condition triggered it: consistent lighting, the actual layout context the material will be seen in (not a flat sample board), a reviewer with the authority to accept or reject what is seen, and a documented record of what was decided and against which lot codes. Without recording which codes were reviewed and what was concluded, a physical review that happens once cannot be relied on for cartons added to the stock later.
Segregate, Transition, Replace or Hold the Stock
Once the lot differences are mapped and, where triggered, physically reviewed, the project has four ways to act on mixed stock, and the choice between them depends on what the review found and what the project can still accommodate.
Segregating by area works where the lots can be assigned to separate rooms, elevations, or runs without breaking a single continuous visual field. This is the least disruptive option because it uses the stock as received; it depends entirely on there being enough distinct areas in the project to absorb each lot separately, and on that split being confirmed against the area schedule rather than assumed.
Approving a deliberate transition works where the visual field is continuous but the project team is willing to accept a visible or planned change partway through — for example switching lots at a natural break such as a doorway or a change in plane, rather than mid-field. This requires someone with acceptance authority to approve the transition point in advance, because an unplanned transition discovered after installation is a different problem than one selected deliberately.
Requesting replacement stock works where neither segregation nor a planned transition is acceptable for the intended area, and where the difference found in review is judged too great to place in a single visual field. This depends on replacement material actually being available that matches the lot already approved, which is a supply question separate from the visual judgment itself.
Holding the mixed stock — pausing installation until one of the other three paths is confirmed — is the appropriate default whenever the review has not yet happened, the acceptance authority has not yet decided, or replacement availability is still unknown. Holding is not a resolution; it is what keeps an unresolved lot difference from becoming an installed one.
None of these four paths should be selected on the basis that matching codes guarantee a visual match, since code equality only confirms that two cartons come from lots the supplier’s system distinguishes in the same way — it does not confirm how similar they look once installed. Equally, a visual match confirmed through review does not by itself resolve caliber, technical, or contractual requirements that may still be open; a lot that reads as visually acceptable can still fail on caliber or on a separate specification requirement, and those checks stay open regardless of what the visual review concludes. What remains project-specific — current stock status, the actual lot codes in hand, the aesthetic intent for the area in question, the sample the project approved, quantities needed, replacement availability, and who holds acceptance authority — is what determines which of the four paths applies, and a supplier conversation grounded in a related guide to confirming product and supplier evidence can help identify which of those items is still missing before a path is chosen.
Frequently Asked Questions
Q: Our approved sample represents one shade lot, but the order includes another. What should we check before using them in a continuous area?
A: Review the lots side by side against the intended visual field before approving the mix. Link the reviewed tiles to their lot IDs and define the lighting, layout context, reviewer and decision in the project record. The same SKU does not make the original sample representative of the additional shade lot.
Q: Does a design with deliberate variation make different shade lots acceptable automatically?
A: No; the intended variation still needs to be compared with the actual material. Confirm whether the selected range and design call for uniformity or variation, then map each lot to the room, elevation or visual field. That comparison supports a deliberate allocation or transition rather than an accidental mix justified by the design description alone.
Q: If the lots look similar in review, can we ignore their different caliber codes?
A: No. A visual decision leaves size-group, technical and contractual requirements separate. Decode the shade, caliber, batch and quality fields using the actual supplier legend and keep any unresolved requirement open. Record precisely what the physical comparison approved so appearance is not used to waive another check.
Q: What options can we discuss if the shade-lot mix is unsuitable for the planned area?
A: Consider segregation by area, an approved deliberate transition, replacement stock or holding the mix. Compare the quantities and area boundaries before choosing a route, and confirm replacement availability for the actual order. For a VITAGRES discussion, the useful inputs are the lot codes, intended visual effect, approved reference and quantities, rather than the SKU alone.