How to prepare artwork for contour cut products

Learn how to prepare print-ready artwork for custom-shaped products like wall stickers, furniture decals and Exoboard.

Get started with our step-by-step guide, or get your file checked by our support team before you submit it.

Building an integration or automated pipeline? Skip straight to the technical reference.

What is contour cutting?

Contour cutting is a print finishing technique in which a printed material is trimmed to a custom shape using a precision cutting machine. Rather than producing a standard rectangle, the cutter follows a defined path – called a cut line or cut contour – to produce any outline the design requires. The result is a finished product whose shape matches the artwork exactly.

Which Prodigi products support contour cutting?

Contour cutting is available for the following print on demand products:

• Wall stickers
• Furniture decals
• Exoboard prints

What should your contour cut file include?

Your artwork and cut path must be combined into a single-page PDF, with both elements kept on separate layers. Here’s how to prepare your file correctly.

Layer 1 – printed design

Your artwork: images, backgrounds and design elements that appear on the finished product.

Layer 2 – cutting instruction

The cut path: a named vector path telling the cutter where to cut. It must not print as a visible border.

Both belong in the same file. Keep them on separate layers and don’t flatten or merge them.

Prepare your file in five steps

Follow these in order, then use the pre-submission checklist below before submitting your PDF.

1. Create your artwork. Work at the finished product size, at 1:1 scale. Use RGB colour mode and at least 300 DPI for raster content.
2. Draw the cut path. Use a smooth vector path, with a 1pt stroke and no fill. Keep the path simple where possible.
3. Name the spot colour CutContour. The name is case-sensitive and must match exactly. Define the swatch as a spot colour, not a process colour. In Adobe Illustrator, set Colour Type to Spot Color.
4. Set overprint and layer order. Set the cut path to overprint and place it on the top layer, above the artwork.
5. Add bleed and export. Extend the artwork at least 1.5mm beyond the cut path on all sides. Export a single-page PDF with vector data and spot colours preserved.

Understanding spot colours and bleed

The cutter looks for the spot colour name CutContour, not the colour’s appearance. Magenta is a useful display convention, not the cutting instruction itself.

Common mistake. A magenta line defined as a process colour may print as a visible pink outline instead of being recognised as a cut instruction.

What about transparent areas?

Transparent areas show the substrate colour – white on most products. They are not see-through unless you’ve selected a clear substrate. White areas can simply show the material rather than printed white ink.

Why simplify the cut path?

Complex shapes with many curves and nodes can slow cutting and increase the risk of errors on fine details. Use your design software’s simplify-path feature where possible.

Document and export settings

Document settings

Document setting	Required value
File format	Single-page PDF
Colour mode	RGB artwork
Raster resolution	Minimum 300 DPI
Scale	1:1 – cut path at the intended finished product size, with artwork extending beyond it for bleed

Export settings

Export setting	Required value
PDF compatibility	PDF/X-4 preferred, or PDF 1.6+
Preserve vector data	On
Downsample images	Off, or Minimum 300 DPI
Flatten transparency	Off
Include spot colours	On

Don’t flatten or rasterise on export. The CutContour path must remain an editable vector path with its spot colour intact.

Troubleshooting common mistakes

A pink outline appears on the printed product

Check that the cut path uses a spot colour rather than a process colour, and that its name is exactly CutContour. Any spelling differences, extra spaces or incorrect capitalisation can prevent the cutter from recognising it.

A white halo appears around the edge

Add at least 1.5mm bleed beyond the cut path on all sides.

The cutter ignores the cut line

Check that the path is a vector, not a rasterised outline, and that spot colours are preserved in the PDF.

The cut lands in the wrong place

Keep artwork and cut path in the same PDF at 1:1 scale, without moving or scaling them separately.

The file is rejected or the cut is the wrong size

Submit a single-page PDF at 1:1 scale, with the cut path at the intended finished product dimensions. Avoid scaling the artwork or cut path during export.

The path is missing after export

Don't merge or flatten layers. Preserve vectors, spot colours and overprint settings.

Pre-submission checklist

Tick off each requirement before uploading your file.

• Single-page PDF at 1:1 scale, with the cut path at the intended finished size
• Colour mode is RGB, resolution 300 DPI minimum
• Artwork extends at least 1.5mm beyond cut line on all sides
• CutContour is a vector path – not rasterised
• Spot colour named exactly CutContour
• CutContour is stroke only – 1pt, no fill
• CutContour is set to overprint
• CutContour is on the top layer
• Layers not flattened or merged
• No transparent areas expected to appear clear (unless clear substrate)
• PDF exported with vectors preserved & spot colours included

Size and shape limits

Very small shapes, sharp corners and narrow protrusions can be difficult to cut cleanly. Keep these minimums in mind when designing your shape.

Got a question?

Our support team can check your file before submission or help troubleshoot your artwork.

Contact support

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Technical reference

Technical guidance for developers and AI agents on generating contour cut print files programmatically. This section translates the guide above into executable specifications.

Canonical PDF specification

Property	Required value
Format	PDF/X-4, single page
Colour space	RGB (artwork) + Separation (cut path)
Resolution	≥ 300 DPI for all raster content
Scale	1:1 – cut path at the intended finished product dimensions, with additional space for bleed where required. No scaling on export
Bleed	Artwork extends ≥ 1.5mm beyond the cut path on all sides
Cut path type	Vector path – not rasterised, not a clipping mask
Cut path colour	PDF Separation colour space, name = CutContour
Cut path stroke	1pt, no fill
Cut path overprint	true (OPM 1)
Cut path z-order	Topmost content stream element

PDF separation colour space

The RIP identifies the named Separation channel CutContour. Its DeviceRGB alternate colour space is a screen-preview fallback, not a process-colour cut instruction.

% Colour space definition
/CutContourCS [/Separation /CutContour /DeviceRGB
  << /FunctionType 2 /Domain [0 1]
     /C0 [1 1 1] /C1 [1 0 1] /N 1 >>]

% In the content stream, to stroke with this colour:
/CutContourCS CS   % Set stroke colour space
1 SC               % Set separation tint to 100%
1 w                % 1pt line width
true OC            % Overprint control
... path operators ...
S                  % Stroke (not fill)

Approach 1: ReportLab

Best for programmatic generation where you control the full pipeline. For complex shapes, replace rect() with moveTo(), lineTo() and curveTo() calls, or convert an SVG path to PDF path operators.

from reportlab.lib.units import mm
from reportlab.lib.colors import CMYKColorSep
from reportlab.pdfgen.canvas import Canvas

# Define the cutter guide spot colour
cutter_spot = CMYKColorSep(
    0, 1, 0, 0,  # visual fallback (magenta)
    spotName='CutContour',
    density=1
)

# Create canvas at exact product size + bleed
product_w, product_h = 85 * mm, 55 * mm  # e.g. card
bleed = 1.5 * mm
canvas_w = product_w + 2 * bleed
canvas_h = product_h + 2 * bleed

c = Canvas('output.pdf', pagesize=(canvas_w, canvas_h))

# 1. Draw artwork (full canvas incl. bleed)
c.drawImage('artwork.png', 0, 0, width=canvas_w, height=canvas_h)

# 2. Draw cutter guide on top
c.setStrokeColor(cutter_spot)
c.setLineWidth(1)  # 1pt
# Rectangle cut path offset by bleed amount
c.rect(bleed, bleed, product_w, product_h, stroke=1, fill=0)

c.save()

Approach 2: SVG to PDF

When artwork originates as SVG, convert to PDF first then inject the spot colour definition in a post-processing step. This keeps design tooling simple and handles the PDF spot colour requirement separately.

Y-axis flip

SVG origin is top-left, Y increases downward. PDF origin is bottom-left, Y increases upward. Flip when converting: pdf_y = page_height - svg_y

# Step 1: Generate SVG with two layers
# - Artwork layer: standard RGB fills and strokes
# - Cut layer: path with class="cut-contour"
#   (use a placeholder colour, e.g. #FF00FF)

# Step 2: Convert SVG to PDF (e.g. via CairoSVG,
# Inkscape CLI, or headless browser)
import cairosvg

cairosvg.svg2pdf(url='design.svg', write_to='intermediate.pdf')

# Step 3: Post-process PDF to replace the RGB magenta
# path with a Separation spot colour. This requires
# manipulating PDF content streams directly (see the
# pikepdf example below).

Approach 3: pikepdf

Use when receiving customer-supplied PDFs or output from design tools that cannot natively create spot colours. Also the recommended approach for the SVG pipeline’s post-processing step.

import pikepdf

pdf = pikepdf.Pdf.open('input.pdf')
page = pdf.pages[0]

# Define Separation colour space for CutContour
sep_cs = pikepdf.Array([
    pikepdf.Name('/Separation'),
    pikepdf.Name('/CutContour'),
    pikepdf.Name('/DeviceRGB'),
    pikepdf.Dictionary({
        '/FunctionType': 2,
        '/Domain': pikepdf.Array([0, 1]),
        '/C0': pikepdf.Array([1, 1, 1]),
        '/C1': pikepdf.Array([1, 0, 1]),
        '/N': 1
    })
])

# Add to page resources
if '/ColorSpace' not in page['/Resources']:
    page['/Resources']['/ColorSpace'] = pikepdf.Dictionary()
page['/Resources']['/ColorSpace']['/CutContourCS'] = sep_cs

# Now rewrite content stream to use /CutContourCS
# for any path that was previously #FF00FF
# (implementation depends on content stream parsing)

pdf.save('output.pdf')

AI agent prompt template

The following system prompt can be passed to an AI agent or LLM to produce a conformant contour cut file.

Create a cut path at the intended finished product dimensions, at 1:1 scale. Extend the artwork at least 1.5mm beyond the cut path on all sides to provide bleed. Add a vector path named "CutContour" as a Separation spot colour with 1pt stroke, no fill, set to overprint. Place the cut path on the topmost layer. Export as a single-page 300 DPI RGB PDF preserving vectors and spot colours (PDF/X-4). The cut path must not print — it is a machine instruction. The spot colour name must be exactly "CutContour" (PascalCase, no spaces or hyphens). Any deviation will cause the RIP to treat it as printable artwork.

Validation

Before submitting a generated file – whether it’s been produced by a script or an AI agent – verify the following programmatically.

• PDF has exactly one page
• Page media box accommodates the cut path at the intended finished product dimensions, plus at least 1.5mm of artwork bleed on all sides
• PDF contains a Separation colour space with the name CutContour
• At least one path uses the CutContour colour space and is stroked (S), not filled (f/F)
• All raster images have resolution ≥ 300 DPI at 1:1 output size
• Cut path bounding box is inset from media box by ≥ 1.5mm
• No path segments have a radius below the minimum for the target substrate

import pikepdf

def validate_contour_cut_pdf(path):
    pdf = pikepdf.Pdf.open(path)
    errors = []

    # Check page count
    if len(pdf.pages) != 1:
        errors.append(f'Expected 1 page, found {len(pdf.pages)}')

    page = pdf.pages[0]
    res = page.get('/Resources', {})
    cs = res.get('/ColorSpace', {})

    # Check for CutContour spot colour
    found_cutter = False
    for name, spec in cs.items():
        if isinstance(spec, pikepdf.Array):
            if (len(spec) >= 2
                    and str(spec[0]) == '/Separation'
                    and str(spec[1]) == '/CutContour'):
                found_cutter = True

    if not found_cutter:
        errors.append('No Separation colour space named CutContour found')

    return errors

Utility functions

Rounded rectangle path generation

Generate a conformant cut path from dimensions and a corner radius, without requiring a designer to draw it manually. Useful for agents producing standard card or sticker shapes programmatically.

def rounded_rect_path(x, y, w, h, r):
    """Generate PDF path operators for a rounded rectangle.
    x,y = bottom-left; w,h = size; r = radius"""
    k = 0.5522847498  # bezier circle approximation constant
    ops = []
    ops.append(f'{x+r} {y} m')  # start
    ops.append(f'{x+w-r} {y} l')  # bottom
    ops.append(
        f'{x+w-r+r*k} {y} '
        f'{x+w} {y+r-r*k} '
        f'{x+w} {y+r} c'  # bottom-right corner
    )
    ops.append(f'{x+w} {y+h-r} l')  # right
    ops.append(
        f'{x+w} {y+h-r+r*k} '
        f'{x+w-r+r*k} {y+h} '
        f'{x+w-r} {y+h} c'  # top-right corner
    )
    ops.append(f'{x+r} {y+h} l')  # top
    ops.append(
        f'{x+r-r*k} {y+h} '
        f'{x} {y+h-r+r*k} '
        f'{x} {y+h-r} c'  # top-left corner
    )
    ops.append(f'{x} {y+r} l')  # left
    ops.append(
        f'{x} {y+r-r*k} '
        f'{x+r-r*k} {y} '
        f'{x+r} {y} c'  # bottom-left corner
    )
    ops.append('h S')  # close and stroke
    return '\n'.join(ops)

SVG to PDF path conversion

When a customer — or an image generation model — provides a shape as an SVG, extract the outermost path and convert it to a PDF vector path with the spot colour applied.

• Parse the SVG and identify the outermost closed path (the silhouette)
• Convert the SVG path data (M,L,C,Z) to PDF operators (m,l,c,h)
• Scale from SVG units (96 DPI) to PDF points (72 DPI): multiply by 0.75
• Flip Y axis: pdf_y = page_height - svg_y
• Apply the Separation spot colour to the converted path
• Append the path to the topmost content stream in the PDF

Got a question?

Our support team can check your file before submission or help troubleshoot your artwork.

Contact support