Sample & Quotation Request Guide for Quality Control & Inspection

What Your Brief Actually Needs to Contain Before We Can Quote Accurately #

Most quotation delays don’t come from the factory side. They come from a brief that’s missing two or three critical inputs, which forces us to make assumptions, and then the quote we send back doesn’t match what the buyer had in mind.

Here’s what we need at the brief stage, grouped by type:

Structural information:
– Finished dimensions (L × W × H in mm), flat or assembled
– Material preference or substrate type — e.g., 350gsm SBS for a folding carton, or 2.0mm greyboard for a rigid box
– Target unit weight or fragile product weight (relevant for insert and die-cut foam specifications)
– Quantity tiers — at minimum, give us two: your initial run and your expected annual volume. A 1,000-unit run versus a 20,000-unit annual volume changes material sourcing, press sheet utilisation, and therefore your unit cost meaningfully.

Print and artwork requirements:
– File format: PDF/X-4 is our preferred submission format for offset litho. Illustrator AI files with embedded links and outlined fonts are acceptable. We do not quote from JPEGs or low-resolution PNGs.
– Minimum resolution for raster elements: 300 dpi at final print size. For surface texture backgrounds that go to the plate edge, 350 dpi.
– Bleed: 3mm on all sides for folding cartons; 5mm for rigid box wrap panels due to board turnover tolerance.
– Colour specification: Pantone PMS codes for brand colours, or CMYK breakdowns with a stated G7-compliant reference condition (typically GRACoL 2013 Coated) if you’re matching to a press standard.

Quantity and delivery:
– Target ex-factory date or in-market date (working backwards, this determines whether standard lead time is viable)
– Destination port and Incoterms preference

If any of these are missing, we will ask. And each round-trip adds 1–3 working days to your timeline.

Supplier Qualification — What to Request and What the Response Tells You #

When you send a sample and quotation request to multiple suppliers, the quality of the response itself is qualifying data.

Ask specifically for a dimensional dieline (cutting die drawing) in CAD or PDF format with all scores, cuts, and glue flaps labelled. A supplier who returns a hand-sketched diagram or a flat image without score notation either doesn’t have a structural engineer on staff or doesn’t do this in-house. Both are relevant to your decision.

Ask for a material data sheet for the proposed substrate. For folding cartons, this should include basis weight (gsm), caliper (mm or pt), brightness (ISO 2470), and burst strength (kPa per ISO 2758). For flexible packaging laminate structures, ask for OTR (oxygen transmission rate, cc/m²/day per ASTM D3985) and WVTR (water vapour transmission rate, g/m²/day per ASTM F1249). A supplier who cannot provide these values against a named standard is sourcing blind.

Ask what AQL level they inspect to at final QC. The answer should reference ANSI/ASQ Z1.4 or GB/T 2828.1 by name, and they should be able to state whether they use Level II general inspection with a specific AQL (typically 1.0 for critical defects, 2.5 for major, 4.0 for minor). If the answer is “we check everything” without a sampling plan, that’s not a QC system — it’s an approximation.

Response time also signals capacity. A quotation for a moderate complexity folding carton (4-colour litho, emboss, spot UV, 10,000 units) should come back within 3–5 working days from a factory with idle capacity and clear workflows. Faster than 24 hours without a clarifying question means the quote was templated, not engineered.

Cost-Performance Trade-offs When Choosing Sample Types #

There are three sample types in our standard process, and understanding what each one costs and what it tells you helps you sequence them correctly.

The counterargument for going straight to a production sample: if you have a stable dieline from a previous supplier and only need to validate colour matching and finish quality on a new source, skipping white sample and digital proof saves 10–15 working days. We see this most often with brands doing a factory transfer rather than a new product launch.

For new launches, skipping the white sample stage is a false economy. Discovering a dimensional mismatch at the production sample stage costs significantly more in material waste and timeline than the white sample fee.

Technical Deep-Dive: How to Evaluate a Received Sample Against Spec #

Receiving a physical sample is only useful if you evaluate it against a defined checklist. We send all outgoing samples with an internal form we call the SP-12 Sample Departure Record, which lists the measurements we confirmed before shipment. When you receive the sample, you’re cross-checking against those declared values.

Here’s how to evaluate systematically:

Dimensional verification. Use a digital calliper. Check finished box height, width, depth. Acceptable tolerance on folding cartons is ±1.5mm per panel. For rigid boxes, lid-to-base gap should sit between 0.3mm and 0.8mm — tighter than 0.3mm and the lid binds in humid conditions; looser than 1.0mm and the box looks underspecified.

Caliper and substrate. For a 350gsm SBS folding carton, confirmed caliper should be 380–420 microns. Anything below 360 microns means the board was either under-spec or moisture-compressed during storage. Check against the material data sheet the supplier provided at quote stage.

Print registration. Hold the box under a loupe or check with a 10× magnifier. Register error above 0.3mm is visible to end consumers and unacceptable on a premium piece. On our sheet-fed offset line, our stated register tolerance is ±0.2mm. Spot UV or foil registration should hold within ±0.25mm of the print layer.

Colour. Compare against your approved Pantone reference under D50 illuminant (standard viewing condition per ISO 3664:2009). Delta-E 2000 (ΔE₀₀) values: ≤1.5 is acceptable for brand-critical colours, ≤3.0 for secondary palette. If you don’t have a spectrophotometer in-house, ask the factory to include a densitometer readout or ΔE report with the sample shipment. We include this as standard on production sample dispatches.

Surface finishing adhesion. For spot UV or soft-touch laminate, run a cross-hatch adhesion test per ASTM D3359. Delamination at grade 3 or below (more than 15% area loss) is a rejection point. For hot foil stamping, check edge definition — bleed beyond 0.1mm at foil boundaries indicates either die temperature was too high or dwell time was excessive.

Structural integrity. For magnetic closure rigid boxes, perform 50 open-close cycles manually and check the hinge crease. Cracking at fewer than 50 cycles indicates the greyboard panel is under 1.8mm or the liner wrap grain direction is running parallel to the hinge score instead of perpendicular.

One dimension we are still tracking internally: ink adhesion on water-based coated surfaces at low temperatures (below 5°C during transit). Our dataset covers 14 lots across 3 substrates, but we need another full winter season to make a firm claim. Use standard tape adhesion test until that data is confirmed.

Specification Notes for Brand Partners #

When you brief us on a packaging QC inspection or sample request, the details that move the process fastest are: finished product dimensions (in mm), substrate preference or reference sample from a current supplier, Pantone or CMYK colour codes with a stated press standard, and your target quantity at two tiers.

The most common brief gap we see is buyers providing dimensions in inches without specifying whether those are internal or external dimensions. For a rigid box, a 200mm external dimension has a very different internal clearance depending on greyboard thickness (1.5mm versus 2.5mm is a 4mm difference in internal space at four walls). Always specify external or internal, and state the product dimensions the box needs to accommodate.

Our standard white sample lead time is 5–8 working days from confirmed brief and approved dieline. Production samples run 15–22 working days from approved digital proof. Timelines extend when artwork arrives in a non-press-ready format, requiring file correction before proofing can begin, which adds 2–4 working days.

What artwork file format should I submit with my sample request?
PDF/X-4 is the format we work from on offset litho jobs. Include a low-res visual reference PDF alongside so our prepress team can confirm layout intent. If you’re working in Illustrator, save as AI with all fonts outlined and links embedded.

The quote I got from another supplier was 40% cheaper — what explains such a large gap?
It depends on whether the cheaper quote specifies the same material grade, the same finishing steps, and the same inspection level. Ask both suppliers to confirm basis weight and caliper for the proposed substrate, and whether spot UV or foil is a full-pass or partial plate. A 40% gap almost always means a different board grade, a single-stage finish where you specified two-stage, or MOQ assumptions that don’t match your stated volume.

How many sample iterations should I expect before approving for production?
For a new product with a new dieline and new artwork, two rounds (white sample, then production sample) is the norm if the brief was complete at the start. Brands that come to us with a fully specified brief, press-ready files, and a clear colour standard typically hit approval in one production sample round. We track this: of projects starting with complete briefs, roughly 65% approve on first production sample.

Can I request a sample before submitting a confirmed order?
White samples and digital proofs are done against a sample fee (refundable against a confirmed order above 3,000 units). Production samples require a written purchase confirmation because press time and materials are committed. We do not run production samples speculatively.

How do I compare quotes fairly across three different suppliers?
Build a specification matrix with these fixed fields: substrate name and gsm, caliper in mm, number of print colours, finishing type and pass count, inspection AQL level, and lead time from approval. Any quote that doesn’t specify all of these has made assumptions on your behalf. Request clarification before comparing unit price.

What is the minimum quantity to get a realistic unit price?
For folding cartons on our standard sheet-fed offset line, price breaks move significantly at 5,000 units, 10,000 units, and 50,000 units. Below 1,000 units, digital print may be more cost-effective than litho offset, but substrate options narrow. For rigid boxes, MOQ typically starts at 500 units for a standard format, 1,000 units for a fully custom die.

What should I do if the received sample doesn’t match the approved Pantone colour?
First, confirm viewing conditions. Check under D50 standard illuminant, not office fluorescent light. If the delta-E₀₀ is above 2.0 on a brand-critical colour under correct viewing conditions, return the sample with a marked colour standard sheet and request a colour-corrected reprint. Include your spectrophotometer readings if available — this shortens the correction cycle because our press team can go straight to curve adjustment rather than re-proofing from scratch.

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Planning a packaging project? Contact our team to request a complimentary specification review and sample quote.