Panel nine, and a client already walking over
The technician was on the ninth panel of a twenty-four panel wall when he phoned. Green, he said.Same batch, same container, same production week. Nobody had done anything wrong, which was the problem. Panel makers bin output by white point, and a batch can legitimately ship anywhere between roughly 6,300 K and 6,800 K. Beside eleven panels at 6,500 K, a 6,800 K panel reads as a colour cast. Nothing defective. The set simply is not matched.
A number ends the meeting, an opinion does not
Colour arguments go nowhere without data. The client says green, the installer says it is the content, and everyone squints at nine panels.With a report you measure the suspect panel, compare it to the sheet, and either recalibrate on the spot or prove the panel matches and the source is at fault. Ten minutes instead of two days.
The limit nobody mentions
A report cannot fix a wall that was never calibrated as a set, and it cannot fix a source outputting AdobeRGB into a wall expecting sRGB.So we ask two questions before installation: will this wall be photographed or broadcast, and who owns the content. If either answer is vague, the report is a document nobody opens.
Why I would now refuse to ship without one
We used the original numbers three years later, when a single panel failed and the replacement had to match panels already in service. Without them we would have been guessing at a colour, and the client would have lost a day of operations.The cost is a colourimeter, a spreadsheet, and somebody willing to stand in a room for six hours. The alternative is an argument you cannot win because you have no evidence.