Medical Device Filing Number Printing: 3 Mandatory Requirements for Class III — Font, Placement, and Contrast — Where Printing Plants Most Commonly Fail: Mismatched Filing Numbers and Instructions for Use

In May 2024, a customer in Wuxi making medical dressings contacted us. The customer said it like this:

"We make Class II medical devices. Our filing number is Suzhou and Wuxi Medical Device Registration Filing 20230123. The filing number was printed on the outer box, but one character was wrong—printed as Suzhou and Wuxi Medical Device Registration Filing 20230132. The drug regulator found it on inspection. The entire batch of 5,000 boxes was returned, with a loss of 12,000 yuan in printing fees plus 20,000 yuan in re-filing costs."

This is a real compliance minefield. The new rules for printing medical device filing numbers on packaging are very clear—font height 1.8mm, contrast ΔE≥5, and position consistent with the manual. But many printers fall on 'one line of the filing number printed wrong.'

Requirement 1: Filing number font height must not be less than 1.8mm

Article 13 of the National Medical Products Administration's "Regulations on the Administration of Instructions and Labels for Medical Devices" (State Food and Drug Administration Order No. 6) reads:

Medical device markings should be clear and easily recognizable...the font height of the filing number should not be less than 1.8 millimeters.

What does 1.8mm actually mean? We measured it with a vernier caliper: it's about the size of 14pt bold (Heiti). Many customers think 14pt is too large and unattractive, and want to shrink it to 9pt—this is non-compliant.

Printers most often fall on these three words:

We recommend printers equip themselves with a 0-150mm vernier caliper and measure the filing number font height before each run. The caliper costs 50 yuan and prevents a single rework loss of 30,000 yuan.

Requirement 2: Contrast between filing number color and background ΔE≥5

This was added to the 2024 new rules; it didn't exist before. The wording is "the filing number color should be clearly distinguishable from the background color."

What does "clearly distinguishable" mean? We measured with a spectrophotometer: the color difference ΔE between filing number and background must be ≥5. If the background is pure white and the filing number is light gray (ΔE less than 3), it is non-compliant.

Printers most often fail in three scenarios:

Our printer's practical experience: it's best to print the filing number in pure black or pure white solid color, guaranteeing ΔE≥10, well above the new rule's limit of 5. Color or hot-foil-stamped filing numbers require separate sample testing for ΔE values.

Requirement 3: Filing number position must be consistent with outer packaging manual

This is the easiest place to crash. The new rules clearly state: the filing number printing position must remain consistent across the outer packaging, manual, intermediate packaging, and small packaging.

What does "consistent" mean? Common customer errors we see:

In March 2025, a customer in Zhejiang making medical masks got caught here: filing number on the outer package was on the back, while the manual was printed on the top of the cover. The drug regulator judged it "inconsistent filing number position," and the entire batch of 8,000 boxes was returned for reprinting.

3 Iron Rules for Printers Taking Medical Device Packaging

Based on the 3 categories of requirements above, we summarize 3 iron rules for printers:

3 More Things Medical Device Packaging Printers Need to Watch

Beyond the 3 mandatory requirements, there are 3 other things printers often overlook:

Further Reading