Before a bulk ACP order, approve a physical colour chip, then a control sample of the exact core, coating and gloss, and for large facades a full-size site mock-up under daylight. Approving from a screen or brochure is how colour disputes start. The control sample becomes the reference the delivered panels are judged against, so both you and the factory should sign and retain one. Here is the sample-to-mock-up sequence that prevents surprises.
Colour chip first, then a real sample
Start with a colour chip or fan deck to pick the RAL and finish family. Then request a physical sample of the exact panel — the real core (FR/A2), coating (PVDF), gloss and RAL — because a colour reads differently on a real panel than on a chip, and gloss changes it again. Approve the panel sample, not just the chip.
The control (retained) sample
Once you approve the sample, both sides should sign and keep a control sample. This is the agreed reference: when the bulk panels arrive, they are checked against it for colour, gloss and finish. Without a signed control sample, “the colour is wrong” becomes an argument with no reference — with one, it is a simple comparison.
Site mock-up for large facades
For a big facade, go beyond a hand sample to a full-size mock-up — a panel or bay installed on site and viewed at distance under daylight. Large areas and real lighting reveal colour batch, gloss and flatness (oil-canning) that a small sample hides. The mock-up is approved before bulk production so any issue is caught cheaply.
Tying samples to the order
Reference the approved sample and control sample in the purchase order, and require the bulk to match it within stated colour (Delta-E) and gloss limits, from one coating batch. This links the thing you approved to the thing you receive, and gives inspection and any warranty claim a clear basis. A real factory welcomes this; it protects both sides.
Frequently asked questions
What samples should I approve before a bulk ACP order? A colour chip to choose, then a physical sample of the exact core, coating, gloss and RAL — and a signed control sample to retain.
What is a control sample? A signed, retained reference sample the delivered bulk panels are checked against for colour, gloss and finish.
When do I need a site mock-up? For large facades — a full-size panel installed and viewed under daylight reveals batch, gloss and flatness a small sample hides.
How do I tie samples to the order? Reference the approved and control samples in the PO and require the bulk to match within colour/gloss limits from one batch.
Related: ACP colour selection · ACP warranty & service life · ACP buyer’s guide.
Talk to the factory: GSM BuildTech (Beijing Guanshimao Technology Co., Ltd.) makes FR aluminium composite panels, PVDF aluminium coil and insulated aluminium panels in Tianjin, China, and welcomes factory audits, samples, mock-ups and third-party inspection. Email sales@insulatedaluminumroof.com or WhatsApp +86 155 2274 6824. See the technical reference & FAQ.