How to Prepare Artwork for Custom Wall Mural Printing: Top 7 File Rules

Rule 1: Build the Artwork to the Final Wall Proportion

Start with the finished wall width and height. Measure the wall at several points because floors, ceilings, and corners may not be perfectly level.

The artwork ratio must match the installation area. For example, a 144-inch-wide by 96-inch-high wall has a 3:2 ratio.

If the source image has another ratio, crop, extend, or reposition it before production. Do not stretch the image to force it into the space, as this may distort objects, patterns, or architectural lines.

Build the mural at 1:1 final dimensions when possible. If the full-size document is too large, use an exact reduced scale and state it clearly.

A 1:10 file should be 10% of the final width and height, with proportionally higher image resolution.

Submit the following information with the artwork:

• Final wall width and height
• Measurement unit, such as inches or millimeters
• A full-wall preview
• The editable source artwork
• The working scale
• The required trimming allowance
• Any areas that must not be cropped

The wall dimensions should also be written in the file name, order sheet, and approval document. This reduces the risk of the wrong dimensions being used during sampling or repeat production.

Rule 2: Check Effective Resolution at Final Size

Resolution is one of the most misunderstood parts of Custom Wall Mural Printing.

A file may display “300 DPI” in its properties and still be too small if its total pixel dimensions cannot support the final mural size.

Raster image resolution is technically measured in pixels per inch, while output devices use dots per inch. The practical production number is the effective PPI after the image has been enlarged.

Buyers can review the Adobe print dimensions and resolution guidance to understand the relationship between pixels, image resolution, and final print size.

Adobe explains that pixel dimensions, print dimensions, and image resolution are directly related. Changing one value can affect the others, especially when resampling is enabled.

For most photographic or illustrated murals, RunpWell recommends starting with approximately 100–150 PPI at final size.

Artwork containing fine linework, small typography, detailed textures, or close-view content may require approximately 150–200 PPI.

Requiring 300 PPI for every wall-size file can create extremely large files without necessarily producing a visible improvement.

Use this formula:

Final PPI = Pixel Width ÷ Final Printed Width in Inches

For example:

• Image width: 15,000 pixels
• Final mural width: 120 inches
• Effective resolution: 125 PPI

Do not judge resolution only by zooming into the image on a screen.

Review a full-size crop at 100% and print a representative sample containing:

• Fine details
• Small text
• Dark areas
• Gradients
• Skin tones
• Fabric or stone textures
• Content positioned near panel seams

A full-size printed sample provides a more reliable quality reference than a small digital preview.

Rule 3: Use Production-Friendly File Formats

The best file format depends on whether the artwork is raster, vector, or a combination of both.

For Custom Wall Mural Printing, a print-ready PDF is often the easiest production file. The editable source file should also be retained in case the prepress team needs to adjust dimensions, panel positions, bleed, or color settings.

Recommended formats include:

• PDF: Consolidated print-ready files
• TIFF: High-resolution raster artwork
• PSD: Layered raster files
• AI: Vector elements, text, and line artwork
• EPS: Compatible vector artwork
• JPEG: Acceptable when resolution and compression quality are sufficient

Avoid repeatedly opening and resaving JPEG files. Each additional compression cycle can reduce detail and create visible artifacts in gradients or textured areas.

When sending editable AI or PSD files, include:

• Linked images
• Required fonts
• Placed graphics
• Texture files
• Embedded color profiles
• A flattened visual reference

For repeat orders, maintain one approved master file with a clear version number.

Use a naming structure such as:

Brand_DesignName_144x96in_Material_V03.pdf

Avoid file names such as:

final.pdf
final-new.pdf
final-latest.pdf
final-corrected-2.pdf

Clear version control reduces the risk of an outdated file being sampled or printed.

Rule 4: Add Bleed and Review Overprint Settings

Bleed is the extra artwork extending beyond the intended trim edge.

The Adobe guidance on printer’s marks and bleeds provides additional information on extending artwork beyond the final trim boundary.

It helps prevent narrow white or unprinted lines when a wall is uneven, an installer needs extra trimming space, or the finished panel shifts slightly during cutting.

Adobe describes bleed as artwork extending beyond the print boundary so that the finished product can be trimmed without leaving unwanted blank edges.

The required bleed amount is not universal. It depends on:

• Final wall dimensions
• Installation method
• Wall accuracy
• Panel width
• Material construction
• Factory cutting workflow
• Whether the mural is trimmed on-site

Ask the manufacturer for the required top, bottom, left, and right allowance before exporting the final file.

Do not confuse these three terms:

Outer Bleed

Extra image around the full outside perimeter of the mural.

Panel Overlap

Repeated image area between two adjoining panels.

Safe Area

The area protecting important content from trim edges, overlaps, and panel seams.

Overprint settings should also be checked before submission.

Unintended overprint can change how white objects, dark text, transparent elements, and overlapping colors appear when printed. Adobe recommends checking artwork with Overprint Preview, while Acrobat Output Preview can be used to simulate print output conditions.

Before exporting, confirm that:

• Important text is outside the trim allowance
• Logos are not too close to panel edges
• White objects are not accidentally set to overprint
• Transparency effects display correctly
• Crop marks do not enter the mural artwork
• The factory receives a clean file and a marked reference preview

Rule 5: Let Production Requirements Control Panel Splitting

Panel splitting should follow the material width, printer capacity, installation direction, seam method, and packaging requirements.

Splitting the artwork before these specifications are confirmed can create unnecessary seams or panels that do not match the factory’s usable print width.

For most Custom Wall Mural Printing projects, submit one continuous master artwork and allow the factory to create the final panel files after the material is selected.

When pre-split files are required, also provide:

• The continuous master file
• A complete panel map
• A small full-wall preview
• The intended installation direction

A reliable panel plan should show:

• Total finished mural width and height
• Total number of panels
• Finished width of each panel
• Left-to-right or right-to-left installation order
• Overlap or butt-joint method
• Panel numbering
• Top and bottom trimming allowance

Avoid placing narrow panels at one edge unless they are necessary. Extremely narrow panels can be harder to install and may make the finished mural look unbalanced.

For e-commerce listings, the installation guide, listing images, and received product should all show the same panel order.

If the product image displays six panels numbered from left to right, the packaged mural should follow that same sequence.

Rule 6: Confirm Color Mode and Approval Standards

Color settings affect Custom Wall Mural Printing, but one conversion rule does not fit every printer, ink system, and wallpaper material.

RGB artwork can contain colors that process inks cannot reproduce exactly. CMYK values also change depending on the selected output profile and printing conditions.

Adobe explains that RGB and CMYK use different color models and that document color spaces affect how colors are displayed and reproduced.

Before converting the file, ask the factory:

• Which color mode is preferred?
• Should the source ICC profile remain embedded?
• Will the factory handle final color conversion?
• Which printer-and-material profile will be used?
• Is a physical color sample required?

A practical workflow is often to preserve and embed the original profile, then allow the production team to complete the final conversion through the approved printer-and-material profile.

Screen approval alone is not enough for branded mural collections.

Monitors have different brightness, contrast, calibration, and color-gamut settings. Wallpaper texture, coating, ink absorption, and lighting can also change the perceived color.

Use one or more of the following approval standards:

• Pantone or another recognized color reference
• A physical printed sample
• An approved master swatch
• A signed sample approval record
• Material and ink specifications
• Batch records for repeat production

RunpWell uses approved samples and production records to support color consistency across repeat orders.

Panels installed together should be printed within the same production batch whenever possible. Buyers should also avoid combining remaining panels from an old batch with newly printed panels on the same wall.

Rule 7: Check Patterns, Seams, and Critical Visual Areas

The final preflight should review the mural as an installed wall, not only as one continuous image.

Straight lines, faces, logos, product features, and small text can look awkward when they cross a panel seam.

Before approving Custom Wall Mural Printing, inspect:

• The complete mural at the correct ratio
• Every proposed panel boundary
• Repeating pattern alignment
• Straight architectural lines
• Faces and focal objects
• Text and logos
• Gradients and dark areas
• Content close to trim edges
• The connection between the first and last panel

For repeating patterns, confirm that the repeat closes correctly both horizontally and vertically.

Look for:

• Broken motifs
• Uneven spacing
• Duplicate objects
• Misaligned lines
• Sudden color changes
• Visible repeat edges

For scenic murals, move important subjects away from panel joints whenever possible.

A full-width miniature proof is useful for reviewing composition and panel order, but it cannot confirm final sharpness.

Use two approval formats:

1. A complete miniature proof for composition and panel positions
2. A 1:1 detail sample printed on the selected production material

The full-size sample should include a representative seam, detailed image area, dark region, and important color reference.