How Small Can Text Be Printed on Packaging: 3 Font Size Standards (Process Limits / Readable Viewing Distance / Audience Differences) — The Question Printers Should Ask Clients

In June 2025, a client selling health supplements sent us a design draft and asked: “Can this ingredient list be made smaller? It currently takes up half the card.”

We reviewed the draft: the ingredient list used No. 5 type (approximately 10.5pt), with tight line spacing, and the smallest line had a text height below 1.2 mm.

We replied: “Yes, but the answer depends on 3 numbers.”

The client probably assumed we would provide a direct answer, but those 3 numbers must be calculated together. This is because the answer to “How small can the text be printed?” depends on 3 completely different constraints, while clients often consider only one of them.

The First Constraint: Process Limit — How Small the Machine and Materials Can Print

The strictest constraint comes from the printing process itself.

How small can offset printing reproduce? Relative dot gain is a key indicator: the usual offset printing limit is 4-5 lines, meaning the smallest stable line width is approximately 0.1-0.125 mm. Converted back to Chinese character strokes, this gives a lower limit of approximately 0.15 mm.

The limits differ by printing process:

To convert stroke width into text height, the stroke width of a common Chinese character is approximately 1/12 to 1/15 of its character height. Therefore, a 0.15 mm stroke corresponds to a text height of approximately 1.8-2.2 mm. This is the process floor for small text in offset printing on ordinary substrates.

However, this number only answers “Can it be printed?” It does not answer “Can it be used once printed?” Being printable and being legible are two different questions.

Another process constraint is easily overlooked: the ink absorbency of the substrate. The edge sharpness of the same stroke differs on coated paper and newsprint, as does its clarity on white board and Kraft paper. If the client changes the paper midway through production, the font sizes must be validated again.

The Second Constraint: Readable Viewing Distance — At What Distance and Angle It Will Be Read

The second constraint comes from the human eye.

One widely cited empirical relationship is that the minimum text height for comfortable reading is approximately 1/300 to 1/200 of the viewing distance.

Applied to actual use cases:

This table explains something printers encounter frequently: the same design can reasonably use No. 5 type for a handheld pharmaceutical instruction leaflet, while using it on a cosmetics box intended for shelf display would be wrong.

Many disputes arise not because the text is too small, but because of a mismatch between the design and its intended use. A designer lays out the artwork on a computer screen where No. 5 type appears clear, even though the box is intended to sit on a shelf 3 meters away and be recognized from a distance.

Reading angle and lighting are additional variables. On matte film over packaging, the same text may remain acceptable one size smaller than on glossy film; light text on a dark background also loses further readability under low-light conditions. Reversed-out text requires an effective text height slightly larger than solid black text.

The Third Constraint: Audience Differences — The Same Product Can Differ Significantly by User Group

The third constraint is determined by the product itself: who will read it?

Products for older adults provide the most typical example. The lens of the human eye loses some ability to accommodate when focusing on nearby small text, so larger text height is required. A smaller pupil and reduced light intake also increase the need for contrast. Our factory's internal benchmark is to increase the text height of instructional content for products intended for users over 60 by 30% to 50% above the standard.

The age-friendly reform of pharmaceutical packaging is an institutionalized example of this constraint. Its large-print version explicitly requires that “the font and format of certain items be enlarged and bolded,” and some pharmaceutical companies have increased the type size from No. 8 to No. 4 and switched to printing on both sides to fit the information into pharmaceutical boxes of the original dimensions.

Audience differences are not limited to age:

The final row is where printers are especially likely to make the wrong decision for clients: printers often take the initiative to reduce prescription drug instructions read by doctors or pharmaceutical information read by pharmacists to the smallest possible size to fit in more content. This is the most dangerous form of font reduction because these readers are precisely the people who can read small text and require complete information.

The Question Printers Should Ask Clients

Combining the 3 constraints, the actual lower limit is the strictest of the three. Take the maximum of the 0.15 mm process-limit stroke, the text height calculated from the readable viewing distance, and the audience enlargement factor.

Clients will not perform this calculation themselves. Therefore, printers should ask the following question:

“Who will read this text, and from what distance?”

Once this question has been answered, the applicable row in the table above is determined, and the strictest lower limit is established.

Our factory records this question in the notes section of the quotation and writes it as a single line: “The minimum text height in this design is X mm (approximately No. Y type), verified against a reading distance of Z mm and target audience W, and producible using the selected process.” The purpose of this line is to provide documented grounds if the client later reduces the text below X during revision.

Returning to the health supplement client mentioned at the beginning, the ingredient list was ultimately not reduced in font size. Instead, it was changed from 2 columns to 3 columns, with “Main Ingredients” and “Excipients” separated into 2 sections. The amount of information was not reduced; it became clearer. The client later said: “You initially said the text could not be made smaller, and I thought you were going to reject the project.”

In reality, the printer was right to reject that font size because it had a clear basis: at that height, the text would blur on coated paper, and after oxidizing for 6 months in storage, its edges would become even rougher. It would be judged “illegible” during inspection, and the printer would have to redo the job.

Further Reading

These articles form a related series with this article:

• 4 Packaging Font Pitfalls That “Look Good to the Client but Print Badly” — choosing the font itself and handling layout details
• 4 Packaging Layout Types — the relationship between font size and layout
• 4 Placement Boundaries for Cosmetic Packaging NMPA Registration Numbers / Filing Numbers — where the 1.8mm font size and 4.5:1 contrast ratio come from
• 3 Practical Boundaries for Age-Friendly Pharmaceutical Instructions — implementation after font size constraints are institutionalized
• 4 High-Risk Label Statements Under Packaging Advertising Law — liability when warning text is too small to recognize