Conclusion first: when a repeat order comes out inconsistent, it is almost never that "this factory's workmanship is unstable". It is that the conditions drifted and nobody recorded the change. Take the same product made twice. The ink came from a different batch, the screen tension changed, the tunnel kiln temperature curve was adjusted slightly, the bottle blanks came from a different supplier. If any one of those changes without being recorded and compared, the colour and the colour registration will differ visibly.
1. Four sources of drift on repeat orders
| Drift item | Typical symptom | What controls it |
|---|---|---|
| Ink batch | Same colour code, but the actual hue differs slightly | Colour-mixing records; ink drawn per order and never mixed across orders |
| Screen condition | Falling screen tension changes ink laydown and blurs the edge of the print | Screens checked for cleanliness and screen tension before use, and replaced promptly when damaged |
| Curing parameters | A change of temperature or time shifts colour depth and adhesion | Process parameter records; the curing curve can be traced back |
| Bottle blank batch | Differences in light transmission and tone are amplified by the printing | Incoming blanks registered by batch and finished goods bound to the batch |
Read that table and the point is clear: repeat-order consistency is not an attitude problem you solve by being more careful. It is a system problem — whether records exist that let you compare one run with the last.
2. Which records actually matter
The company's external position is that quality recording covers colour-mixing records, process parameter records, first-article approval and in-process inspection, across the whole chain. Broken down, each record answers one repeat-order risk:
- Colour-mixing records: next time the same colour code comes up, the previous formula is pulled out instead of colour matching being repeated.
- Process parameter records: equipment settings and temperature-zone values are carried over from last time, rather than being adjusted again "by feel".
- First-article approval: a repeat order is still first-article checked, compared against the retained first article from last time rather than by eye alone.
- In-process inspection: patrol inspection at a fixed frequency catches drift early.
Retention is specified as well: order files, quality inspection records and retained-sample labels must be kept for at least 3 months, and after each batch passes inspection one sample is kept as a bulk-production sample for long-term archive. Those three months of records and the bulk-production sample are the colour reference for the next repeat order.
3. Ink and screens are the most easily overlooked part
The internal rules are detailed on these two items:
- Ink is drawn against the production order in the matching model, logged on issue, and must not be mixed.
- Every screen is checked for cleanliness and screen tension before use; mesh clogging or damage means prompt replacement.
- Ink and screens are stored bound to their machine, with labels, and must not be stored loose with the materials of other equipment.
- Ink consistency is re-checked proactively at fixed intervals so that ink condition does not cause a whole batch to fail.
These rules look trivial, but they map directly onto repeat-order drift: mixing ink and storing screens loose are the two most common reasons "this time is not like last time".
4. How buyers can protect repeat-order consistency in the cooperation
- When placing the order, ask for the previous parameters to be carried over, and write into the contract or order that the previous records may be reused.
- Require a fresh first-article check on repeat orders: ask for the repeat-order first article to be confirmed against the previous bulk-production sample.
- Specify batch binding: ask clearly which blank batch and which ink batch this batch of finished goods corresponds to.
- Keep your own bulk-production sample: hold one signed sample yourself so that a dispute has a shared reference.
- Material changes must be notified: if the supplier changes the ink brand or batch, it should tell you in advance.
5. How to handle a problem on a repeat order
If a colour difference or a registration problem does happen, watch the order in which the supplier reacts — that tells you whether it is reliable. Does it check the records first, compare the first article and trace the issue to a machine and a batch, or does it look for excuses and blame the glass? The company's approach is to use system records to find the cause. That is how one print-blur problem on 2,000 of 160,000 essential-oil bottles shipped to France was traced within 5 minutes to the batch, the packing operator, the production time, the machine, the responsible person and the patrol inspector. Repeat-order consistency never rests on memory; it rests on records. If a supplier can still explain, three years later, exactly how an order was run — from its records — that is what stability means.