How to Prepare a Design for Printing on Flexible Packaging

On screen, the design looks perfect: the logo is in place, the colors are rich, and the product photo is sharp. But after transferring the graphics to an actual package, it suddenly turns out that the logo partially overlaps the seal, small text ends up on a fold, the barcode scans poorly, and the color looks nothing like what was shown on the monitor.

The reason for such situations is not always the printing itself. Often, the problem appears much earlier — when the flexible packaging design was created like a regular advertising layout without taking into account the construction of the future package and the production technology.

Therefore, preparing a layout for flexographic printing does not begin with choosing a photograph, font, or brand color. First, you need to determine the material, packaging size, construction, seals, folds, perforation, web direction, and packing method. Only after that should the design be placed on the technical keyline.

Let us go through the entire process step by step.

Start Not with the Design, but with the Packaging Construction

One of the most common mistakes is when a designer receives a task such as “make a 250 × 400 mm bag” and starts drawing.

But two dimensions are not enough.

Before creating the layout, you need to determine:

• whether it is roll film or a ready-made bag;
• flat or cone-shaped bag;
• whether a bottom gusset is required;
• width and height;
• seal positions;
• seal type;
• whether a valve is required;
• euro slot;
• reinforcing tape;
• technical holes;
• perforation;
• sealed or open bottom;
• web direction;
• cutting position;
• print repeat.

For example, a flat bag may have three or four seals, a bottom gusset, a valve, technical holes, or a euro slot. If the designer does not know exactly where these elements will be located, they are essentially working blindly.

That is why professional layout preparation for flexographic printing requires a technical keyline.

What Is a Technical Keyline?

A technical keyline is a diagram of the future packaging showing:

• contours;
• cutting lines;
• seals;
• folds;
• sealing zones;
• additional structural elements;
• working design area.

An important rule: do not create the keyline yourself without confirmation.

The optimal solution is to obtain or approve the technical keyline with the packaging manufacturer. At Artha-S, bag construction and technical parameters are defined before final design preparation.

Mark All Technical Zones

Once the keyline is ready, the design area should be separated from the technological elements.

The layout should preferably show separately:

• cutting line;
• side seals;
• bottom seal;
• fold positions;
• bottom gusset;
• valve;
• euro slot;
• perforation area;
• eye mark, if used by packaging equipment;
• safe area;
• roll unwinding direction.

Particular care should be taken when placing the logo, legally important text, barcode, and QR code.

They should not be placed too close to a seal, fold, or cutting line.

At the same time, there is no universal rule such as “keep a 5 mm margin” for all packaging. The safe area depends on the bag construction, equipment, and production technology. It is better to confirm it with a technologist.

Choose the Material Before Finalizing Colors

The same design can look different on different films. Therefore, material comes first, and the final color decision comes after.

Artha-S works, among other materials, with BOPP, CPP, and PE.

Transparent BOPP Film

BOPP is biaxially oriented polypropylene film. It has high transparency, characteristic gloss, attractive appearance, tear strength, and good barrier properties.

The Artha-S product training specifies a BOPP thickness of 15 to 40 microns.

For a designer, the main feature of transparent BOPP is obvious: the packaging background is essentially absent.

This allows transparent windows through which the customer can see the product. At the same time, it also means that the color of the product inside can affect the perception of the printed design.

Therefore, the layout should separately define:

• transparent windows;
• areas with white underprint;
• elements without white underprint;
• areas where the product should remain visible.

White and Pearlized BOPP

A light base provides a more predictable background for color printing.

However, white and pearlized films are not the same as a regular “white sheet.” The material has its own optical characteristics that should be considered when selecting shades.

Metallized BOPP

A metallized surface makes it possible to create interesting decorative effects.

For example, part of the metallic shine can be left exposed, while white ink can be applied beneath other elements.

Therefore, the designer should clearly specify:

where white underprint is required and where the metallized material effect should remain visible.

Matte BOPP

A matte surface makes it possible to achieve a more restrained and often more premium visual appearance.

Artha-S works with transparent, white, pearlized, metallized, and matte BOPP film.

CPP

CPP is a more elastic polypropylene film. It offers high mechanical strength, transparency, resistance to acids and fats, and heat-sealing capability.

The Artha-S product file specifies CPP thickness of 15–40 microns.

Microperforation can also be applied to CPP, allowing the material to be used for applications where additional airflow is required.

PE

Polyethylene is used where flexibility, mechanical strength, water resistance, and strong welded joints are especially important.

For PE, working parameters are selected depending on the specific task and packaging construction.

Corona Treatment and Heat-Sealing Layer Are Not the Same Thing

These concepts are sometimes confused.

Corona treatment is required so that ink adheres properly to the surface of the film. The Artha-S product training states that the BOPP activation layer is created using corona discharge.

The heat-sealing layer performs a different function — it is required for sealing seams during product packaging.

In other words:

activation → printing;

heat-sealing layer → seam formation.

Before starting the design, it is necessary to understand which side of the material is treated, which side is sealable, and where the inner and outer sides of the packaging will be.

Surface or Reverse Printing

This is another decision that should be made before final layout preparation.

With surface printing, the ink is applied to the outer side of the film.

With reverse printing, the image is applied to the inner side of transparent film and is viewed through the material.

Reverse printing is often used in laminated structures where the ink is placed between material layers.

It cannot be said that one method is always better. The choice depends on packaging construction and intended use.

Before preparing the layout, it is necessary to confirm:

• printing side;
• corona-treated side;
• inner and outer side of the material;
• heat-sealing side;
• need for lamination.

An important detail: in Artha-S production training, lamination is indicated as an operation performed through a subcontractor.

What File Format Should Be Supplied?

The best option is to provide a design file that can be properly checked and prepared for production.

Recommended formats:

• editable Adobe Illustrator — AI;
• prepared PDF;
• PDF/X approved with the prepress department.

What About JPG or PNG?

They can be sent, but more as a reference.

JPG, PNG, screenshot, or photograph of the design should not be the only production file for a complex layout.

Why?

They may lack:

• vector logo;
• correct color separation;
• spot colors;
• separate white underprint;
• technical layers;
• sufficient graphic quality.

What About Canva?

A layout made in Canva can be used as a base or concept. But before production, it requires a prepress check.

Colors, fonts, image resolution, technical keyline, and construction zones should be checked especially carefully.

Work at 1:1 Scale

Unless otherwise agreed with the manufacturer, the layout should preferably be created at actual size — 1:1.

It is convenient to work in millimeters.

The technical keyline should not be arbitrarily scaled after work begins.

Layers should also be organized logically:

• construction;
• main design;
• texts;
• white underprint;
• special inks;
• technical elements.

The eye mark, white underprint, cutting contour, or technical markings should not accidentally be merged with the background graphics.

The cleaner the file is organized, the easier it is to check.

CMYK, Pantone, and RGB: How to Prepare Colors

Color on a monitor and color on film are different things.

CMYK

Photographs, multicolor illustrations, and many gradients are prepared for process CMYK printing.

Pantone and Spot Colors

Separately mixed inks should be used when a specific brand shade is critical.

For example:

• logo color;
• key brand color;
• consistent shade across different SKUs;
• white ink;
• decorative color.

Artha-S performs flexographic printing up to 8 colors.

But “up to eight” does not mean that every package needs eight inks. The number is determined by the specific design and technology.

RGB

RGB is designed primarily for screens.

Therefore, RGB elements should not be left in the final production layout without checking. A color that glows brightly on a monitor cannot necessarily be reproduced exactly with printing inks.

White Underprint on Transparent Film

This is one of the most important details in BOPP film design.

On white paper, the white background already exists. On transparent film, it does not.

Therefore, white may be printed as a separate ink.

It is needed, for example, to:

• make the logo more opaque;
• prevent the product color from altering the design;
• create a white information area;
• achieve predictable shades of other inks.

The white underprint should be placed on a separate layer or defined as a spot color.

It is also important to remember that white may count toward the total number of printing inks.

Photographs: 300 ppi Is a Good Guideline, but Not a Magic Button

The photograph on the packaging should be high quality at the final scale.

As a practical guideline for color photographs, approximately 300 ppi can be used unless the prepress department specifies otherwise.

Bad workflow:

small photo from a messenger → enlarged several times → packaging.

Good workflow:

original high-quality photo → correct scaling → color preparation → check in the final PDF.

Also, do not forget to include linked files in the layout package.

Fonts, Thin Lines, and Small Text

Fonts in the final file can be:

• converted to outlines;
• or properly embedded in the PDF.

Before converting text to outlines, always save an editable original.

Particular care should be taken with:

• very small text;
• thin lines;
• white text on a colored background;
• text built from multiple printing inks.

There is no point in setting a universal rule such as “no smaller than 6 pt.” The actual minimum font size depends on the specific font, inks, material, and print configuration.

Therefore, minimum parameters should be agreed with an Artha-S technologist before producing printing plates.

Gradients, Shadows, and Transparencies

Complex effects are another risk area.

Potential problems include:

• abrupt transitions in gradients;
• banding;
• incorrect transparency flattening;
• accidental overprint;
• complex blending modes.

Therefore, the design must be checked after export to the final PDF.

Especially if the layout contains large solid fills, transparencies, or complex transitions.

Barcode and QR Code: Looking Good Is Not the Main Goal

The main purpose of a barcode is to scan.

Do not:

• stretch the code disproportionately;
• place it too close to other elements;
• place it on a seal;
• place it across a fold;
• place it in a perforation area;
• use a background with insufficient contrast.

A Quiet Zone — a clear area — should be left around the barcode.

The safest basic option is dark bars on a light background.

The QR code should also have a clear zone around it.

Most importantly, it should be checked not only on screen but also on a real printed packaging sample.

What to Consider in Labeling

Packaging may include:

• product name;
• net weight;
• ingredients;
• nutritional and energy value;
• allergens;
• storage conditions;
• manufacturer information;
• date coding area;
• batch number;
• barcode;
• instructions;
• contact details;
• material designation.

This is not a universal legal list.

Specific requirements depend on the product and target market, so the customer or relevant specialist should verify the labeling content.

Table: What to Prepare and Where Mistakes Most Often Occur

Layout Element	What Needs to Be Prepared	Typical Mistake
Keyline	Exact dimensions, seals, folds, cutting	Design created without construction
Colors	CMYK and approved spot colors	RGB left in the layout
White underprint	Separate layer or special ink	White not included in color count
Photographs	High-quality files at final scale	Small photo heavily enlarged
Fonts	Outlined or embedded fonts	Font is replaced when opening
Logo	Vector file	Small PNG/JPG used
Barcode	Contrast, Quiet Zone, correct position	Code overlaps a seal
Transparent areas	Clearly marked	Window accidentally covered with white
Perforation	Hole area shown on keyline	Holes pass through text
Roll	Unwinding direction and repeat	Design comes out upside down

Preflight: 14 Checks Before Sending the Layout

Before sending the file to the manufacturer, go through this list:

1. The document size matches the technical keyline.
2. Seals, folds, and cutting are marked.
3. Safe areas are defined.
4. Unwinding direction is approved.
5. Colors are converted to CMYK or defined as spot colors.
6. There are no accidental RGB objects.
7. White underprint is placed separately.
8. Fonts are converted to outlines or embedded.
9. Linked images are included.
10. Photographs have sufficient quality.
11. Gradients, transparencies, and overprint are checked.
12. Barcode and QR code have the required clear zones.
13. Text does not overlap seals, folds, or perforation.
14. A control PDF is prepared.

And one more important check is technological. Even a properly prepared graphic file must be evaluated from the perspective of future production.

What to Provide to the Designer or Manufacturer

To avoid collecting information piece by piece after work begins, it is better to prepare the following in advance:

• vector logo;
• brand guidelines;
• names of brand colors;
• final texts;
• barcode in high-quality format;
• original photographs;
• examples of the desired style;
• product information;
• required labeling;
• packaging format;
• dimensions;
• material;
• thickness;
• bag construction;
• packaging line information;
• unwinding direction;
• desired number of colors;
• planned production run.

How Layout Work Is Organized at Artha-S

The process can be conditionally divided into 11 steps:

1. The customer describes the product and task.

2. Material and thickness are agreed.

3. Packaging format is defined.

4. Seals, folds, valve, bottom gusset, perforation, and other structural elements are agreed.

5. The technical keyline is prepared or approved.

6. The customer provides the finished design or source materials.

7. The layout goes through a prepress check: colors, fonts, images, barcode, white underprint, and technical zones.

8. The number of printing inks is determined.

9. The final layout is approved before photopolymer plate production.

10. Machine setup and production run are performed.

11. If required, further slitting, perforation, and bag manufacturing are carried out.

This approach is significantly cheaper than discovering an error after the plates have been produced or after the print run has started.

Artha-S Technical Capabilities

For printing on flexible packaging, Artha-S uses flexographic technology — direct rotary printing with fast-drying liquid inks using elastic photopolymer plates.

Printing is performed in “roll-to-roll” format.

Main capabilities:

• flexographic printing — up to 8 colors;
• material width for printing — 300–1200 mm;
• work with BOPP, CPP, and PE;
• BOPP — 15–40 microns;
• CPP — 15–40 microns;
• transparent, white, pearlized, metallized, and matte BOPP;
• surface treatment for printing;
• heat-sealing layer when required;
• roll slitting;
• hot perforation;
• cold euro perforation;
• production of flat and cone-shaped bags.

Printing equipment: Flexotechnika Tachys, FDR 850/6, FPHS-6HS.

Slitting allows work with material up to 1200 mm wide and 15–100 microns thick.

Artha-S hot perforation is performed with 1 mm holes for material thickness of 20–55 microns. Cold euro perforation is performed with 4–5 mm holes for material thickness of 20–80 microns.

Lamination, when required, is organized through a subcontractor.

The minimum order quantity depends on the material, number of inks, packaging construction, and additional operations. The current MOQ is clarified after reviewing the layout and technical specification.

13 Common Packaging Design Mistakes

Problems most often occur when:

1. The design was created without a technical keyline.
2. The logo was supplied as a small JPG.
3. RGB was left in the production file.
4. White underprint was not planned.
5. Important text was placed on a seal.
6. The barcode has no Quiet Zone.
7. Transparent windows were not marked.
8. Fonts were neither embedded nor converted to outlines.
9. Linked photo files are missing.
10. The unwinding direction was not approved.
11. Perforation or euro slot was not taken into account.
12. Color is evaluated only by looking at the monitor.
13. Printing plates are produced before final approval of the texts.

Most of these mistakes are easy to correct before printing. After plate production or after the print run begins, corrections become much more expensive.

FAQ

What Format Is Best for Sending the Design?

Ideally, an editable AI file and a control PDF. The specific PDF/X standard should preferably be agreed in advance with the prepress department.

Can I Send a Layout Made in Canva?

Yes, as a base or reference. But before production, a technical check of colors, fonts, photographs, keyline, and technical zones is required.

Do Fonts Need to Be Converted to Outlines?

For the final production file, this is often convenient. At the same time, it is essential to keep a separate editable original.

Why Can the Color on Packaging Differ from the Monitor?

A monitor works in RGB and emits light. The flexographic printing result depends on inks, material, substrate color, white underprint, and production parameters.

Does White Ink Count Toward the Eight Colors?

On transparent or metallized film, white underprint may be a separate printing ink. This must be taken into account during color separation and calculation.

What Is the Minimum Font Size That Can Be Used?

There is no single value. Everything depends on the typeface, printing method, color structure, and specific equipment configuration. It is better to confirm this with a technologist.

How Should a Barcode Be Checked?

Maintain proportions, ensure sufficient contrast, leave a Quiet Zone, and do not place the code on a seal or fold. Final verification should be performed on a printed sample.

Can Photographs Be Printed on Flexible Packaging?

Yes. A high-quality original, proper color preparation, and an understanding of how the image will look on the selected material are required.

Conclusion

A good packaging print layout is not simply a beautiful design. It is a file in which graphics work together with the bag construction, material, and production equipment.

Therefore, the correct sequence looks like this:

product → material → construction → technical keyline → design → prepress check → printing plates → flexographic printing.

This helps avoid cropped logos, barcode problems, incorrect transparent areas, unexpected colors, and expensive rework after production has started.

Do you already have a finished design or only an idea for future packaging? Send Artha-S information about the product, bag format, material, dimensions, and layout. The specialists will check the technical zones, colors, and file preparation, help determine the optimal number of inks, and prepare a production run quotation.