Author: Site Editor Publish Time: 23-02-2026 Origin: Site
In the packaging industry, the biggest headache for brands isn't price, but rather the pungent smell and heartbreaking color discrepancies that greet you when you open a large box after weeks of waiting.
Packaging is a brand's first impression; a loss in sensory appeal (sight and smell) instantly destroys a product's premium value. Today, we won't talk about empty slogans; we'll take a frontline perspective from factory production to break down how to nip these two "after-sales nightmares" in the bud.
Color difference is a physical phenomenon that is almost unavoidable in flexographic or gravure printing, but a scientific quality control system separates "reasonable color difference" from "defective products."
Many people overlook the fact that the same ink printed on transparent PE, frosted OPP, or kraft paper will produce completely different effects.
Solution: Always require the supplier to produce a sample on the same material. Don't rely on the RGB color chart on your computer, or even blindly trust paper Pantone color charts, because the ink absorption and light transmittance of the plastic film will change the physical representation of the color.
In mass production, as machines operate at high speeds, the solvent in the ink evaporates, causing the ink to thicken (viscosity changes), resulting in increasingly darker colors over time.
Expert Advice: Inquire with your supplier whether they have an automatic viscosity control system. Workshops relying on manual experience to add solvent can hardly guarantee that the color of the ten-thousandth bag will match the first bag.
The error in color perception by the naked eye is extremely large (affected by light, mood, and fatigue).
A core standard: Excellent factories use spectrophotometers. By measuring the L*a*b** values, they control the color difference within Delta E < 2.0 (or the industry-standard range).
If your packaging bags are used to hold food, clothing, or cosmetics, the odor is not only a matter of user experience but also involves compliance risks related to solvent residue.
Packaging bag printing typically uses solvents such as toluene and methyl ethyl ketone (MEK). If the drying tunnel is too short, the temperature is insufficient, or the machine speed is too high, the solvent cannot completely evaporate and remains trapped inside the roll.
Solution: Confirm whether the manufacturer uses solvent-free lamination technology. This is currently the most thorough solution to odor problems, eliminating residue at the source by eliminating solvent-based adhesives.
Some factories, in order to reduce costs, mix "secondary materials" or "recycled materials" into their raw materials. These plastics, which have undergone secondary melting, will produce a thermal decomposition odor.
Identification Tips: Bags made from pure virgin material have good tensile strength and a very faint, non-pungent odor. If there is a noticeable burnt or musty smell when the bag is torn open, it can be basically concluded that recycled materials have been added.
Ordinary inks contain heavy metals and volatile organic compounds (VOCs).
Advanced Requirements: Prioritize environmentally friendly water-based inks or soybean-based inks. Although slightly more expensive, this is the best way to mitigate odor and export risks in today's increasingly stringent environmental regulations.
To avoid making mistakes in large-scale production, you only need to ask your supplier these three crucial questions before placing an order:
"How do you monitor the dynamic value of Delta E in color difference during the production process?"
"Is your lamination process dry lamination or solvent-free lamination?"
"Can you provide a solvent residue test report (GC test) from a third-party institution?"
Professional suppliers will respect you for these questions and will not dare to be careless in the production process.
