Preparing files for flexo printing on film: NEX PRINT guidelines

The rules we check in PDF Check before a job goes on press. Values for PE, PP and PET film and paper, Kablonex machine park. Reading time: 8 minutes, time saved: 1-2 days per round of corrections.

1. Geometry and repeat 2. File 3. Colours 4. Minimum sizes 5. Who does what 6. Checklist 7. FAQ

Reversed-out text 0.15 mm thick, an EAN code in red, a gradient down to 0%, a 333 mm design on a 1000 mm repeat: these are four typical reasons why a file goes back to the customer with a list of corrections. None of them is creative, each of them costs a day or two.

370-1350mm repeat (depending on the press)

up to 10colours on the Miraflex

72 hPDF Check + Technical Fit

0.2 mmmin. positive line

1.Before you open Illustrator: geometry and repeat

Flexo prints from a sleeve with a fixed circumference. The length of your design must be a multiple of the available repeat, otherwise you get waste or the package dimension changes. This is the first thing to agree with purchasing, not the last.

Parameter	Miraflex / Novoflex (CI)	Bonardi	Flexa (stack)
Repeat	370-1130 / 370-1250 mm, sleeves per list (incl. 400, 500, 600, 650, 700, 800, 900, 1030, 1130)	400, 420, 500, 600, 800, 900 mm	450-1350 mm
Print width	400-1300 mm	250-1800 mm	up to 400 mm (tube), up to 1300 mm (flat)
Colours	10 / 8	6	6
Substrates	PE, PP, PET, PA*, paper	PE	PE, PP, BOPP
Tube / two-sided print	yes / yes (10/10, Miraflex)	yes / yes (3/3)	yes / yes

Sleeve circumference correction: -10 / +5 mm. * PA: range depends on configuration.

Rule of thumb: design length × number of designs per revolution = repeat ± 5 mm. Example: 250 mm design → 500 mm repeat (2 designs) or 1000 mm (4 designs on the Flexa). 333 mm design → 670 mm (2 × 335 mm, +4 mm correction).

You set the design dimension together with the dieline (package layout): cut lines, seals, folds, perforations, unprinted area under the seal. The dieline is supplied by Kablonex or by the manufacturer of your packaging machine. Do not design to the finished bag size “by eye”.

Check the repeat in the configurator

2.File format and structure

File

PDF/X-4 (preferred) or PDF/X-1a from a vector file: Illustrator, ArtPro+, InDesign.
Scale 1:1, units in mm, no marks inside the design.
For complex files: source package (.ai + links + fonts).
Name: customer_product_size_version_date.pdf.

Geometry

Dieline on a separate layer, spot colour “Dieline”, overprint, non-printing.
3 mm bleed beyond the cut line for solids and backgrounds.
5 mm safe zone from seals and design edges for text, codes, logos.
Fonts outlined or embedded; for variable text include the fonts.

We do not accept for printing: files from Canva, PowerPoint, Word, JPG/PNG as the main artwork, PDF exported from a browser preview. Send them as a brief; the production file will be prepared by your studio or our prepress (additional service).

3.Colours and separations

The number of separations in the file is the number of printing units you occupy on the press, and therefore directly the cost and availability of the press. A product photo on transparent film is CMYK + white = 5 separations, with a brand colour 6: that is already the limit of the Bonardi and the Flexa.

1 colour = 1 name

Each Pantone as a separate spot colour, no duplicates (“PANTONE 485 C” and “P 485” are two separations in the RIP).Line artwork: Pantone. Photos: CMYK, plus Pantone for the brand colour if repeatability is required.

Opaque white

On transparent film a separate “White” separation, no screen, no fine detail.State in the brief: surface print or reverse print (laminate, reverse, mirror image).

Black

Text: 100 K. Rich black only in large solids, e.g. 60 C 40 M 100 K; the build is agreed at the first order.

Overprint

Only intentional. Accidental overprint on white text = the text disappears. Trapping (0.2-0.3 mm) is set by our prepress; do not add your own.

Screen 2-98%

A dot below 2% does not transfer to film, above 95% it fills in. End a gradient “to zero” with the background colour or change the design.Screen ruling typically 40-54 l/cm on film; NEX PRINT prepress selects it for the specific substrate.

Metallic, pearl

No screen, no fine text, outside the seal zone.

4.Minimum sizes: lines, text, codes

During printing dots and lines grow (dot gain), and a polymer plate will not hold detail below the threshold. On PE film, especially on tube, tolerances are wider than on a paper label.

Element	Minimum	Note
Positive line	0.2 mm	one colour
Negative (reversed) line	0.3-0.4 mm	a reverse out of several colours at once increases the registration risk: avoid
Positive text	5-6 pt	no thin serifs or light weights
Reversed text	7-8 pt semibold	in one colour, never out of CMYK
Text in opaque white	7 pt	no screen
EAN-13 code	scale 100-120% (absolute min. 85%)	bars parallel to the printing direction, one dark colour on a light background, quiet zone min. 3.6 mm, no red or pastels
Bar Width Reduction	set by NEX PRINT prepress	typically 20-40 µm, depending on substrate and plate
Registration spacing	≥ 0.3 mm	indicative registration tolerance between colours; the value for a specific press is given by the technologist

Raster images: min. 300 ppi at 1:1 scale, CMYK, no profiles embedded in objects, no lossy compression. Higher resolution does not help: detail below the screen ruling will not transfer to film anyway.

5.What you do, what we do

Stage	Who	Time
Preflight per checklist (section 6)	You / your studio	30 min
PDF Check + Technical Fit Assessment: separations, geometry, codes, repeat	NEX PRINT technologist	up to 72 h, report with a list of corrections
Trapping, plate distortion, BWR, step and repeat	NEX PRINT prepress	in process
Contract proof / ink drawdown / press proof	NEX PRINT	per order, sample from 14 working days

You do not calculate distortion yourself: prepress scales the artwork in the sleeve circumference direction depending on plate and mounting tape thickness. Your file should be at nominal size. The Miraflex inspects PDF files and barcodes in-line, so an error in a code stops the job before it leaves the press, not after delivery.

6.Checklist before sending

PDF/X-4, 1:1, from a vector file, name with version and date.

Dieline on a separate layer, as a spot colour set to overprint.

3 mm bleed, 5 mm safe zone from seals.

Design length matches the repeat (checked in the configurator).

Number of separations = number of colours in the order, one name per colour, white as a separate separation.

No RGB, text black 100 K, no accidental overprints.

Screen within 2-98%.

Lines ≥ 0.2 mm (positive) / 0.3-0.4 mm (reversed), text ≥ 5-6 pt / 7-8 pt.

EAN: scale, colour, direction, quiet zone.

Images 300 ppi CMYK, fonts outlined or included.

In the brief: substrate, thickness, surface or reverse print, quantity, deadline.

Interactive checklist with a readiness score

7.Frequently asked questions

Can I send a file from Canva or PowerPoint?

Not for printing. Send it as a brief, and the production file will be prepared by your studio or our prepress (additional service, quoted with the order).

How many colours do I need for a product photo on transparent film?

CMYK + opaque white = 5 separations, with a brand colour 6. That is the limit of the Bonardi and the Flexa; the Miraflex gives headroom up to 10 colours.

Does printing on tube limit the artwork?

Yes. Registration and print width (up to 400 mm on the Flexa) are tighter than on flat web. Avoid fine reversed text and thin lines running across the fold.

Will I get a proof before printing?

Yes: a contract proof for CMYK, an ink drawdown for Pantone, a press proof on request. Plan it in the schedule: sample from 14 working days.

What about PPWR markings on the package?

The requirements of Article 12 (labelling) depend on delegated acts that are not yet finalised. Reserve space for pictograms in the safe zone and come back to the topic before printing.

Have a file? We will check it within 72 h.

We send back a report with a list of corrections and a preliminary match to the press, not a “file rejected”. No obligations, no price on the screen: the quotation comes back together with the report.

Send files for PDF Check Check packaging feasibility

Machine parameters per the NEX PRINT technical sheet (RW_2025_12_15). Threshold values (lines, text, screen, EAN) per industry practice for flexo on film; binding parameters for your order are confirmed by the NEX PRINT technologist in PDF Check.

Products

Services