Preparing Files for Print¶

Your artwork looks perfect on screen. Then the print arrives and the fine hatching in the shadows has turned into a dark smear, the delicate Trace outlines have vanished, and the background texture that looked subtle at 100% zoom is invisible on paper. The screen lied. Not because the software was wrong, but because screens and presses speak different languages, and translation takes deliberate preparation.

This article covers every setting and decision between "I'm happy with this on screen" and "this printed exactly as intended."

Vector vs. Raster: The Format Decision¶

Vexy Lines produces vector output (SVG, PDF, EPS) and raster output (PNG, JPEG). The choice depends on your printing method.

Format	Type	When to Use	When to Avoid
PDF	Vector	Offset printing, digital press, large format, archival	When the print shop specifically requests another format
SVG	Vector	Further editing before print, web-to-print services	Direct submission to most commercial printers (they prefer PDF)
EPS	Vector	Legacy print workflows, older RIP software	Modern workflows (EPS is being phased out)
PNG	Raster	Inkjet printing, online print services, social media	Offset or large-format where resolution matters
JPEG	Raster	Quick proofs, email previews	Any final print production (JPEG compression damages line art)

The default recommendation: PDF for print. It embeds vector data, handles colour profiles, and is universally accepted by print shops.

Resolution: What Applies and What Doesn't¶

Vector output from Vexy Lines is resolution-independent. A PDF of your engraving contains mathematical curve definitions, not pixels. It prints at the resolution of the press (2400 DPI on an offset press, 1200 DPI on a digital press) regardless of any resolution setting in Vexy Lines.

When does resolution matter? Only when exporting raster formats (PNG, JPEG). For raster exports:

Print Type	Required DPI	Notes
Offset printing	300 DPI	Industry standard for halftone reproduction
Digital press	300 DPI	Same standard, easier to exceed
Large format (banners, posters viewed from distance)	150 DPI	Viewers stand 1–3 metres away; 150 DPI is indistinguishable from 300 at that distance
Very large format (billboards)	72–100 DPI	Viewed from 5+ metres. Even 72 DPI looks sharp.
Fine art / giclée	300–360 DPI	Matches inkjet printer native resolution

For vector exports (PDF, SVG, EPS), ignore DPI entirely. The printer's RIP handles resolution.

Canvas Size and Physical Dimensions¶

Before exporting, set your canvas size to match the final print dimensions. If your poster is 18 × 24 inches, set the canvas to 18 × 24 inches. This ensures:

Fill intervals are physically accurate. An interval of 1.5 mm in the document is 1.5 mm on the print.
Stroke thicknesses are correct. A 0.3 mm outline is 0.3 mm on paper.
The print shop doesn't need to scale your file, which can introduce unwanted thickness changes.

If you've been working at a different canvas size (e.g., a smaller size for faster rendering), scale the canvas to the final print size before exporting. Re-render all fills after resizing to recalculate stroke positions at the correct dimensions.

Bleed and Trim¶

If your artwork extends to the edge of the printed piece (no white border), you need bleed: extra artwork that extends beyond the trim line.

What is bleed?¶

Printing presses don't cut with pixel-perfect precision. The cut can drift by 1–2 mm. If your artwork stops exactly at the trim line and the cut drifts inward, a sliver of white paper appears at the edge. Bleed prevents this by extending artwork 3–5 mm beyond the trim.

Adding bleed in Vexy Lines¶

Set your canvas size to the final trim size plus bleed on all sides. For a 210 × 297 mm (A4) print with 3 mm bleed: set canvas to 216 × 303 mm.
Extend all fills to cover the bleed area. Make sure no fill stops at the trim boundary: every fill that touches an edge must extend to the canvas edge (which is now 3 mm beyond the trim).
Adjust masks to cover the bleed area. If a fill is masked to the background, extend that mask 3 mm beyond where the trim will be.

Trim marks¶

Some print shops want trim marks (small lines indicating where to cut) embedded in the file. Others add their own. Ask before adding. If needed, create a thin-stroke rectangle at the trim dimensions on a separate layer, with crop marks extending into the bleed.

Colour: RGB to CMYK¶

Vexy Lines works in RGB colour space. Most commercial printing uses CMYK (Cyan, Magenta, Yellow, Key/Black). The conversion matters because some RGB colours (particularly bright blues, greens, and oranges) don't have exact CMYK equivalents. They shift during conversion, sometimes noticeably.

For single-colour (black) artwork¶

No conversion needed. Export with strokes set to pure black (R:0, G:0, B:0). In CMYK, this maps to K:100 (pure black ink), the cleanest possible print.

If you want a richer black (for large solid areas), some printers prefer "rich black" (C:40, M:30, Y:30, K:100). But for line art, pure K:100 is standard and avoids registration issues between colour plates.

For multi-colour artwork¶

Option 1: Let the print shop convert. Export your RGB PDF and tell the printer "please convert to CMYK using [profile]." The most common profile for coated paper is US Web Coated (SWOP) v2 or ISO Coated v2 300%. For uncoated paper, use US Web Uncoated or ISO Uncoated.

Option 2: Convert before sending. Open your exported PDF in Acrobat Pro, Illustrator, or Affinity Publisher and convert to the appropriate CMYK profile. Compare the before and after. If any colours shift unacceptably, adjust them in Vexy Lines and re-export.

For spot colours (screen printing, Pantone)¶

Use solid flat colours in Vexy Lines (no Dynamic Color). Name your colours to match Pantone references if required. Export as PDF or SVG and communicate the Pantone numbers to the printer separately.

Stroke Thickness for Reproduction¶

The minimum printable stroke thickness depends on the printing method:

Method	Minimum Stroke	Notes
Offset (coated paper)	0.15 mm	Excellent fine-detail reproduction
Offset (uncoated paper)	0.2 mm	Ink spreads slightly on absorbent paper
Digital press (laser)	0.2 mm	Toner particles limit fine detail
Digital press (inkjet)	0.25 mm	Ink dot size limits resolution
Large format (solvent/eco-solvent)	0.5 mm	Lower resolution heads
Screen printing	0.3–0.5 mm	Mesh count dependent; see Preparing for Screen Printing

Check your Stroke Thickness Min in the Properties Panel. If it's below the minimum for your print method, increase it. Strokes below the printable minimum will either vanish or bleed into their neighbours.

Large Format Considerations¶

Printing at poster, banner, or wall-mural scale introduces specific adjustments:

Widen your intervals¶

A 1.5 mm interval that looks detailed on an A4 print looks dense and muddy on a 2-metre-wide banner. Scale intervals up proportionally:

Print Size	Interval Multiplier	Example
A4 (210 mm)	1.0× (baseline)	1.5 mm
A2 (420 mm)	1.5–2.0×	2.2–3.0 mm
A0 (841 mm)	2.5–3.5×	3.7–5.2 mm
2 metres+	4–6×	6–9 mm

These are guidelines, not rules. The right interval depends on viewing distance. A poster in a hallway (viewed at 1 metre) needs finer detail than a banner on a building (viewed at 20 metres).

Increase stroke thickness proportionally¶

If intervals double, stroke thicknesses should roughly double too. Otherwise, the strokes become invisibly thin relative to the gaps.

Test at actual size¶

If you can't print a full-size proof, print a portion at 1:1 scale on standard paper. A 30 × 30 cm section of your banner, printed at actual size, shows you exactly what the final output will look like in that area.

Proofing at 100%¶

The most common print preparation mistake: evaluating artwork at the wrong zoom level.

Always proof at 100% (actual pixels or actual size). At 100% zoom, 1 mm on screen ≈ 1 mm on paper (assuming your screen is roughly calibrated). This shows you the physical stroke spacing and thickness at print scale.

At 50% zoom, strokes look twice as close together and twice as thin as they'll actually print. You'll think the artwork needs more density and increase it. Then the print comes out too dark.

At 200% zoom, strokes look twice as far apart and twice as thick. You'll think the artwork needs less density and decrease it. Then the print comes out too light.

Zoom to 100%. Evaluate. Then export.

If your canvas is larger than your screen at 100%, pan across it in sections. The whole composition matters, but detail quality matters more, and detail quality is only visible at 100%.

Packaging: What to Send the Printer¶

A print-ready submission includes:

Item	Purpose
PDF file (or SVG/EPS if requested)	The artwork
Proof image (low-res PNG or JPEG)	Visual reference for the printer to compare against
Specifications document	Trim size, bleed, colour mode, spot colours, paper stock, quantity
Font info	Not applicable for Vexy Lines (all text is outlines), but note this if the print shop asks

Specifications to communicate¶

Trim size: 210 × 297 mm (or whatever your target is)
Bleed: 3 mm (or 5 mm, per printer's request)
Colour mode: CMYK (or specify spot colours)
Paper stock: Coated / uncoated / textured / coloured
Quantity: Number of prints
Special finishes: Foil stamping, embossing, spot UV (if applicable)

Screen Print Specifics¶

For screen printing preparation, see Preparing for Screen Printing. The key additional requirements:

Separate files per colour
Colour coding for screens
Registration marks
Trapping at colour boundaries
Interval sizing for mesh count

Pre-Flight Checklist¶

Before sending any file to a printer:

[ ] Canvas size matches trim dimensions (plus bleed if applicable)
[ ] All fills have been refreshed at final canvas size
[ ] Stroke thicknesses are above the minimum for the print method
[ ] Intervals look correct at 100% zoom
[ ] Colour mode is appropriate (RGB for digital, CMYK for offset, spot for screen)
[ ] No elements extend beyond the canvas (unless intentional bleed)
[ ] Export format is PDF (or as specified by the printer)
[ ] A proof image is included for visual reference
[ ] Specifications are documented and attached

Summary¶

Decision	Rule of Thumb
Format	PDF for print, SVG for editing, PNG for screen
DPI (raster only)	300 for standard, 150 for large format
Bleed	3–5 mm on all sides if art extends to edge
Minimum stroke	0.15–0.5 mm depending on print method
Colour	Pure K:100 for black, CMYK profile for colour, Pantone for spot
Large format intervals	Multiply baseline by 2–6× depending on size
Proof zoom	Always 100% (actual size)

Next: Gallery of Techniques