How do you prepare a graphic design for a label intended for flexographic printing?
Flexographic printing is the dominant technology in the production of self-adhesive labels and flexible packaging—it accounts for most of the labels we see on store shelves. A label design prepared for flexography must take into account the specific characteristics of this technology—because what looks great on a monitor and in a laser printout may look completely different once transferred to a flexographic press. Preparing labels for printing is the stage where a graphic designer’s good intentions clash with the physical limitations of the process—and the designs that win out are those created from the outset with flexography’s capabilities in mind.
The Basics of Flexographic Printing – What Does a Graphic Designer Need to Know?
Flexographic printing uses flexible printing plates with a raised image—the ink applied to the raised elements is transferred directly to the substrate (paper, film, laminate). This means that each color in the design requires a separate plate—and each plate entails cost and time. A design with twelve Pantone colors requires twelve plates and twelve printing stations—which may exceed the machine’s capacity (standard flexographic machines have six to eight stations).
The resolution of flexographic printing is lower than that of offset or digital printing—typically 133–150 lpi (lines per inch) compared to 175–300 lpi in offset. This means that fine details (thin lines, small text, subtle gradients) may be lost or blurred. The minimum line width for a positive image (dark on a light background) is 0.15 mm—for a negative image (light on a dark background), 0.2 mm. Text smaller than six points (positive) or eight points (negative) becomes illegible—not because of a printing error, but due to the physical limitations of the process.
Dot gain is a phenomenon characteristic of flexography—the printed dot appears larger than the dot on the plate because the flexible printing form flattens slightly under pressure. A 50% dot on the plate may result in a 70–75% dot on the print—which means darker colors, lower contrast, and loss of detail in the shadows. The graphic designer must account for dot gain during the design process—by lightening colors by 15–25% compared to the desired print result and avoiding dot values above 85% (as they approach full coverage and lose detail).
Trapping is a technique that compensates for color registration inaccuracies—involving a slight overlap of adjacent colors at their boundaries. In flexography, trapping should be at least 0.15–0.25 mm—without it, even the slightest misalignment between printing stations creates visible white gaps between colors. Modern graphic design software (Adobe Illustrator, ArtPro+) includes tools for automatic trapping—but it’s worth consulting the values with the print shop, as the optimal trapping size depends on the machine and the material.
Preparing Files for Label Printing
Preparing for label printing using flexographic technology begins with selecting a color space. Spot colors (Pantone) are the standard in flexography—they provide consistent, vibrant colors without registration issues. Process printing (CMYK) is possible on flexographic presses with precise registration—but requires calibration for the specific press and substrate.
We accept print files from Illustrator and Photoshop, preferably saved in PDF format. All fonts should be converted to curves, and images should be embedded in the file. The die line must be on a separate layer—it cannot be part of the artwork, as it will appear on the print.
When preparing a PDF file, include 1.5 mm bleed on all sides and use the CMYK color space or specified PANTONE colors.
The text on the label should be vector-based (not raster-based)—vectors produce sharp edges regardless of resolution. Fonts converted to curves eliminate the problem of missing fonts at the print shop. Text in process colors (e.g., black text printed with four CMYK colors) is risky—even a slight misalignment results in visible colored outlines. Print black text using a single color (100% K or spot black)—this eliminates the misalignment issue.
White elements on metallic or transparent substrates require a white underprint—because the substrate material is not white, and colors printed directly on it lose intensity and purity. A white underprint adds one printing station to the process, but it is essential for accurate color reproduction on non-standard substrates. The graphic designer should prepare a separate layer with a white underprint—0.1–0.2 mm smaller than the color layer—so that the white edges do not extend beyond the graphic in case of misregistration.
Coating (UV varnish, matte varnish, spot varnish) is a finishing process that enhances the appearance and durability of the label. Spot varnish (gloss on selected elements, matte on the rest) requires an additional plate and printing station—we plan for it from the design stage, not as an afterthought. Selective varnish areas should have simple geometry—complex shapes with thin elements make it difficult to align the varnish with the graphics.
Barcodes and QR codes require special attention when preparing labels for printing. The minimum module width (the thinnest bar in the code) is 0.25 mm—below this value, the scanner may not read the code. We design barcodes in the direction of printing (so-called picket fence orientation)—bars parallel to the direction of web travel. Code orientation perpendicular to the print direction (ladder orientation) is acceptable, but requires tighter tolerances and better process control.
Working with a flexographic printing company: what to discuss before starting a project
The substrate material affects the final result—matte paper absorbs ink differently than polyethylene film, which alters color saturation and halftone rendering. A design created for paper will not automatically translate to film without adjustments—which is why changing the substrate during the design process requires recalibrating colors and verifying the legibility of details.
Before a graphic designer opens the design software, they should obtain technical specifications from the print shop: the number of available printing stations, maximum halftone resolution, halftone type (conventional, stochastic, hybrid), the dot gain value for the specific machine and material, minimum text sizes and line thicknesses, and trapping requirements.
A color proof is a step that should not be skipped—but a digital proof (from an inkjet printer) does not accurately reflect the results of flexographic printing. A proof produced on a flexographic press (machine proof) is more expensive, but it provides a realistic representation of how the label will look in mass production. For high-volume projects (tens of thousands of running meters), the cost of a press proof is a negligible part of the budget—and it can prevent a costly mishap in the production run.
Label versioning (different language, flavor, or weight variants on the same plate) requires planning from the graphic design stage—variable elements should be grouped in a single area of the label to minimize the number of plate changes. Flexographic printing handles versioning well when the design is prepared with this feature in mind—and becomes a logistical nightmare when the graphic designer changes an element in a different place on each version.
Flexographic printing is a technology that rewards thorough preparation and penalizes the disregard of its limitations. A label design created for flexographic printing from the very first sketch—taking into account dot gain, trapping, resolution limitations, and the number of colors—comes off the press exactly as the designer intended. A design prepared without knowledge of these limitations loses detail, shifts colors, and generates complaints—and corrections during production cost many times more than consulting with the printer during the design phase. A good label graphic designer does not need to be a flexographic press operator—but must understand its limitations and capabilities well enough to design within them rather than fighting them after the fact.
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