Many chain brands and long-term repeat customers have reported visible color differences between two batches of the same acrylic printing products, suspecting inconsistent color matching by the factory. In reality, five factors—board batch differences, ink, workshop environment, printing parameters, and observation lighting—can all cause color deviations. There is a reasonable color difference range in the industry. Below, we break down the causes of color differences and the factory's standardized color control solutions to help customers objectively judge the finished products during acceptance.
Board batch differences are the primary cause. Even for new transparent acrylic of the same specification, slight variations in base color exist between different production batches. Some boards have a slight bluish tint, while others are slightly warmer, which alters the color of the top ink when light penetrates. Frosted boards and colored boards have uneven base colors in each batch, naturally resulting in color deviations under the same printing parameters. Thicker boards have lower transparency, so the same ink will produce deeper colors compared to thinner boards. If customers switch board thickness for repeat orders, the color difference will be more noticeable. Factory solution: Long-term repeat customers can fix the same board supplier and lock the same batch of raw materials, retaining sample boards for subsequent production. When mixing multiple batches of boards, ink concentration can be slightly adjusted in advance to compensate for base color differences.
UV ink consumption and batch changes affect color. When ink reserves in the ink tank are insufficient, the ink output becomes unstable, resulting in a pale appearance. When switching to a new batch of ink, slight differences in pigment ratio can cause overall color bias. Shangsheng workshop replaces the ink with a new batch before each production run, prints color samples in advance, and replenishes ink when the remaining amount falls below one-third to avoid gradual transitions, color breaks, or paler shades due to mid-production ink shortage.
Workshop temperature and humidity, as well as curing parameters, interfere with color development. In high-temperature and humid environments, ink curing slows down, resulting in paler colors. In low-temperature and dry environments, ink cures quickly, producing richer colors. Batch production workshops maintain a fixed temperature and humidity for printing areas, with temperatures controlled between 22-26°C and humidity between 50%-60%. After UV lamp tubes age and their light intensity decreases, ink curing becomes insufficient, causing grayish colors. The workshop calibrates UV lamp power monthly and replaces aging tubes to ensure uniform curing parameters for each batch.
Differences in observation lighting can easily lead to misjudging color differences. Under three types of lighting—cool white office lights, warm yellow store lights, and workshop natural light—the same printed board appears completely different. Under cool light, blue tones are enhanced, while under warm light, red and yellow tones are more vivid. Brands strictly match colors for orders, and factories compare color cards under standard D65 natural light. At the same time, they send standard samples to customers, who should check the samples under natural light during acceptance to avoid misjudging color differences under single lighting conditions.
Industry-standard reasonable color difference specifications: For regular display items, the color difference ΔE≤5, with no noticeable difference when viewed from a distance under natural light; chain brand VI standard colors are strictly controlled at ΔE≤3, with one sample out of every 50 retained, archived for one year, and subsequent repurchases can directly adjust colors based on old samples. While it's impossible to achieve zero color difference, reputable factories can control deviations within a range that is difficult for the naked eye to distinguish. Shangsheng Acrylic retains exclusive color samples and printing parameter archives for large orders, allowing repurchase orders to directly access archived parameters to minimize batch color differences as much as possible. Additionally, it supports free pre-production color samples for mass production, with customers confirming the color before proceeding to production to avoid color inconsistencies in the entire batch.
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