What design files need to be prepared before label printing?

Why Are File Specifications Important?

In label printing, design files are the key bridge connecting creativity and production. A source file that meets printing specifications can go directly into the production process without repeated communication and revisions. Conversely, issues such as incorrect file format, wrong color mode, or missing bleed areas may require file modifications that delay delivery, or in severe cases, result in scrapped printed products.

According to statistics, approximately 60% of design files received by label printing companies have varying degrees of specification issues. Mastering file preparation essentials in advance can reduce rework communication costs by at least 90%.

File Format Selection

PDF format is preferred, especially PDF/X-1a or PDF/X-4 standards. These two formats are the universal exchange standards in the printing industry, embedding all fonts and images to ensure consistency when opened on different computers and software. When exporting PDF, choose the "Print Quality" or "High Quality Print" preset without compressing image data.

AI (Adobe Illustrator) or CDR (CorelDRAW) source files are secondary options, preserving all layers, editable text, and linked images, making it convenient for the printing company to make fine adjustments to file details. Both software are vector design tools, suitable for labels and other files that require precise dimensions and graphics.

Directly sending JPG or PNG image files is not recommended. Images are pixel-based and show jagged edges and blurriness when enlarged. When content involving text is output in image format, text edges also become blurred, affecting the fineness of the finished label.

Color Mode: CMYK Is the Only Choice

All design files must use CMYK color mode. RGB is a screen display mode with a wide color gamut but cannot be printed. When converting from RGB to CMYK, colors will change significantly—bright blue becomes dark gray, bright green becomes dark green, and fluorescent colors disappear entirely.

For LOGOs and brand primary colors in label design, it is recommended to use PANTONE spot color codes for annotation. Spot color printing has more controllable color difference, and brand color accuracy is higher than four-color overprinting. Create new spot color swatches in the file; do not set spot colors as CMYK mixed color mode, otherwise the spot color plate cannot be identified.

All embedded images in the design must also be in CMYK mode. If images come from the internet or mobile phone photography, they are usually in RGB or sRGB and need to be converted to CMYK before placing them in the design file.

Bleed Area and Crop Marks

Bleed area is the portion of design content that extends beyond the final cutting size, preventing white edges from showing due to cutting precision deviations. For label printing, it is recommended to leave a 2mm bleed on all four sides; for special-shaped or rounded corner labels, 3mm is recommended.

Setup method: When creating a new file, set the finished size (e.g., 100×50mm), and extend 2mm of bleed on each side of the artboard. Mark two lines in the design draft—the inner one is the crop line (finished line), and the outer one is the bleed line. All background colors and graphics extending to the edge must cover up to the bleed line.

Important text and LOGOs should be at least 2mm from the crop line to avoid cutting deviations that cut into key content. The barcodes or QR codes on labels should have a quiet zone of at least 3mm around them to ensure scanning and reading rates.

Text and Image Processing

All text must be converted to outlines (create outlines). If files are sent without outline conversion and the printing company lacks the corresponding fonts when opening, they will be automatically replaced with other fonts, causing layout misalignment or garbled text. After outline conversion, it is recommended to check page by page for any missed text conversions—select the text and check the properties panel; if it shows as a path rather than a font, the outline conversion is successful.

Embedded image resolution should not be lower than 300dpi. For LOGOs and product photos involved in label printing, if sourced from the internet (usually 72dpi) or mobile phone photography, high-resolution versions need to be recreated before placement.

Line thickness should not be less than 0.2pt (approximately 0.07mm); overly thin lines are prone to breaking or being lost during printing and die-cutting. For reverse text (knockout white), the font size is recommended to be no less than 8pt, with moderate stroke width—too small and fine reverse text is easily filled in by ink and difficult to read.

File Checklist

Before sending files, check item by item according to the following checklist: ☐ File format is PDF/X-1a/X-4 or AI/CDR source document; ☐ Color mode is CMYK, no RGB mode colors or images; ☐ 2-3mm bleed reserved on all four sides, background color extends to the bleed line; ☐ All text has been converted to outlines (create outlines); ☐ Image resolution ≥ 300dpi; ☐ Important content is ≥ 2mm from the crop line; ☐ Spot colors have been set as spot color channels and annotated with PANTONE color codes; ☐ No hidden layers or unnecessary reference lines in the file; ☐ File naming includes product name and date (e.g., BrandLabel_20260714.pdf).

Label design files prepared according to the above checklist can go directly into the printing company's production process without repeated communication and revisions. If you still have questions about file specifications, you can request specific design template files from the printing company. Designing based on the template can minimize specification issues to the greatest extent.