3 Regulatory Requirements for Printing Cosmetic Filing Numbers on Packaging: Font Height / Color Contrast / Placement — Printers Most Often Slip on Contrast

A skincare customer in Suzhou last year had a batch of finished products returned by the market regulator. It wasn't to do with the formula or the ingredients list, but with the line «National Cosmetic Special Word 2024XXXX» on the back of the packaging box that couldn't be clearly read. The customer's original words: «I printed the filing number — who would have guessed it also requires contrast against the background color.» This customer is not an isolated case. Since the formal implementation of the «Cosmetic Supervision and Administration Regulations» in 2021, rework on filing number printing has become a common complaint for printers.

What a Filing Number Is — It's Not Text, It's a Regulatory Carrier

Many people treat the filing number as ordinary informational text. They are wrong. The filing number is a mandatory identifier stipulated in Article 32 of the State Council's «Cosmetic Supervision and Administration Regulations», uniformly issued by the NMPA: domestic ordinary cosmetics correspond to «Province Abbreviation + G + ZWBZ + 4-digit year + 6-digit serial number», special cosmetics correspond to «National Cosmetic Special Word + 4-digit year + 4-digit serial number», and imports correspond to «National Cosmetic Import Word / National Cosmetic Special Import Word». These three types of numbers have no pattern, and printers cannot predict the number of characters in advance. However, regulations have clear requirements on its physical presentation.

The special feature of this filing number field is that it does not belong to «product information», but is the physical presentation of an «administrative license number» — essentially the same type as the SC number for food and the registration certificate number for medical devices. This means regulatory requirements are higher than for brand-customized content, and printers must treat it as a compliance item rather than a design item.

3 Mandatory Requirements — Font Size Is Not the Biggest Issue

What actually trips up printers is not the font size, but two other commonly overlooked parameters. Article 17 of the «Cosmetic Labeling Management Measures» (effective from May 1, 2022) has three specific provisions:

First, placement must be independently marked. The filing number cannot be hidden in the ingredients list, nor stuffed under the barcode area; it must be presented as an independent block with clear visual separation from other content. A common mistake: to save space, the printer places the filing number in the gap between the barcode and the ingredients list, with a font size of less than 1mm.

Second, color contrast has a numerical requirement. The technical interpretation document cites the GB/T 39728-2020 standard: contrast between filing number text and background color must be ≥ 4.5:1 (WCAG AA standard). This means light gray text on white background will not pass — pure black or dark color (RGB 0,0,0 or brightness ratio over 4.5x) is required.

Third, the minimum font size is tied to readability. The regulations don't directly stipulate font size, but require the filing number to be clearly legible and not easily erased. Industry practice uses 1.5mm character height as the lower limit, corresponding to 8-point font; small packages (less than 15cm²) allow 1.0mm. If the customer's original design draft specifies 0.8mm, it must be sent back for rework.

The Trap Printers Most Often Fall Into — Contrast Is Not «Looks Clear»

Last year, a Zhejiang color cosmetics customer finished a batch of lipstick boxes with hot-stamped gold filing number on light pink background. The eye could identify it, but measured digital contrast was only 2.8:1, far below 4.5:1. When drug administration sampled the inspection, it was directly judged as non-compliant marking — not because it couldn't be read, but because the contrast was poor.

Practical checks for printers: ① Run contrast check with AI or Illustrator's contrast detection tool when the file is handed over, marking those < 4.5 in red for feedback; ② If the customer insists on special processes (hot stamping, silver stamping, partial UV), risks must be clearly communicated and the customer must confirm in writing that «they are aware the contrast may not meet the standard and voluntarily assume compliance risks»; ③ During the proofing stage, a separate color sample must be made for the filing number area, so the customer can review under natural light rather than just looking at the screen proof.

Differentiated Handling for Two Types of Customer Scenarios

Brand customers (self-designed) and OEM customers (with design drafts provided by the OEM) have entirely different approaches. Brand customers usually have their own design specifications, but the design end doesn't understand the GB/T 39728 contrast algorithm, so the printer needs to proactively intercept during review. OEM designers may not be aware that the filing number must be processed separately, so the printer should directly provide a template: independent block, placement (bottom 1/3 or top of back), font size 1.5mm+, color pure black or dark color with brightness ratio ≥ 4.5x.

If the design specifies font size exceeding 3mm, placement on the front or side, independent block, without hot stamping or silver stamping — all pass. If it uses hot stamping, has poor contrast, small fonts, or is hidden in a corner — 100% requires rework.

Further Reading

4 Identification Standards for Cosmetic Labels: Ingredients / Shelf Life / Batch Number / Usage Method

4 Types of EU Compliance Requirements for Cosmetic Packaging: REACH / EC 1223/2009 / 94/62/EC / EN 13427

3 Categories of Cosmetic Packaging Regulations: Cosmetic Supervision Regulations + Children's Cosmetics + Labeling Measures

6 Categories of Mandatory Identifications on Food Packaging: Ingredients / Allergens / Shelf Life / Nutrition / Net Content / Origin