How to Prepare Your Artwork for Ceramic Decal Printing

Resolution: why 300 DPI is a minimum, not a target

DPI (dots per inch) refers to how much detail your image contains relative to its printed size. A 300 DPI image at 4" × 4" contains 1,200 × 1,200 pixels. A 72 DPI image (the standard for web graphics) at the same size contains only 288 × 288 pixels — barely enough to print legibly at 1" × 1".

The rule: measure your design at its printed size, not its digital canvas size. A design that's 4,000 pixels wide sounds high resolution — but if you're printing it at 24 inches wide, that's only 167 DPI, which will print noticeably soft.

How to check in Photoshop:

1. Image → Image Size
2. Uncheck "Resample"
3. Change Width or Height to your intended print dimensions
4. Read the Resolution field — it should say 300 or more

How to check in Illustrator:

1. Select the placed image
2. Window → Document Info
3. Look for "Effective PPI" — should be 300+

For hand-drawn work: Scan at 600 DPI in grayscale or color, then reduce to 300 DPI if your file is too large to work with. The original scan captures more detail that you can then finalize.

For photography: Phone cameras at full resolution are typically fine for decal printing at smaller sizes. A 12-megapixel phone produces a file with enough resolution for an approximately 8" × 10" print at 300 DPI.

Color mode: why CMYK matters

Digital ceramic decal printing uses a CMYK (Cyan, Magenta, Yellow, Black) process. If you design in RGB (which is the default for most digital tools), your colors will be converted to CMYK when the printer processes the file — and that conversion often changes colors in ways you don't expect, particularly:

• Bright oranges shift toward brown or tan
• Vivid purples become more muted
• Electric blues lose saturation
• Neon or fluorescent colors are not reproducible in CMYK at all

The fix: Design in CMYK from the start so you see approximately what will print.

In Photoshop: File → New → Color Mode → CMYK Color In Illustrator: File → New → Color Mode → CMYK

In Procreate: Go to Canvas → Canvas Properties → Color Profile → select any CMYK profile (Generic CMYK is fine for starting). Note: Procreate's CMYK support is limited — for critical color work, finish in Photoshop.

In Canva: Canva is RGB-only. Colors converted during printing may shift. For casual designs with muted palettes, Canva files often work fine. For designs where color accuracy matters, use Photoshop or Illustrator.

The ceramic color gamut: managing expectations

Even with perfect CMYK files, ceramic decals fire differently from what you see on screen. This is because the color you see on your monitor is produced by light, while ceramic decals use metallic oxide pigments that behave differently at kiln temperatures.

General rules:

• Colors fire darker and more muted than they appear on screen
• Warm tones (red, orange) are the most variable — the magenta + yellow combination produces warm reds but not the vivid cadmium reds of commercial ceramics
• Blues and greens fire most accurately to screen representation
• Very pale tints (anything above 90% lightness) may fire nearly invisible
• Black fires reliably as a deep, dark tone

Practical adjustment: Increase brightness and saturation by 20–30% in your working file before submitting. Lighten shadows. This partially compensates for the darkening that happens during firing.

Best practice: Order a test sheet before committing to a full production run on a new design. Fire it on a sample tile with the same glaze you'll use in production. Use that fired result as your color reference going forward.

White: the most misunderstood part of ceramic decal printing

This is the single issue that surprises first-time decal users most often.

There is no white in digital CMYK ceramic decal printing.

White ink or toner doesn't exist in the standard CMYK ceramic system. Where you leave areas white in your design, the decal paper (and therefore the underlying glaze surface) will show through. This is not a mistake — it's how the process works, and with planning, it's an asset.

What this means for your design:

• White backgrounds: A white background in your Illustrator or Photoshop file will fire transparent, revealing the glaze color underneath
• White text or linework: Same — will be invisible unless the glaze is dark enough to provide contrast
• Highlights and light areas in photography: Will become more transparent, potentially revealing the glaze surface

How to work with it:

• Design for the glaze color. If you're applying to a white glaze, transparency reads as white and works naturally. If you're applying to a colored or dark glaze, plan your design accordingly.
• Use the glaze as part of the design. Leave intentional "windows" in the decal to let the glaze color show through as a design element.
• For light-on-dark applications: Consider underglaze transfers (which can be printed with opaque light colors) or a different decal type if white areas are critical to your design.

Setting up your file in Photoshop

1. New document: File → New. Set width × height to your design size. Resolution: 300 DPI. Color Mode: CMYK Color. Background: White (you'll see it as white but it fires transparent).

1. Color profile: Edit → Color Settings → Working Spaces → CMYK → U.S. Web Coated (SWOP) v2. This is the standard for ceramic digital printing.

1. Design your artwork as you normally would.

1. Adjust for firing: When finished, add a Brightness/Contrast adjustment layer. Increase brightness +15 to +25. Increase contrast slightly if needed. This compensates for the darkening during firing.

1. Save as: File → Save As → PDF (Photoshop PDF), or TIFF at 300 DPI. Flatten layers if requested by your printer.

Setting up your file in Illustrator

1. New document: File → New. Select Print preset or manually set width/height. Color Mode: CMYK. Raster Effects: 300 PPI.

1. Artwork: Create your vector artwork. For placed images (photos, scanned artwork), ensure they are 300+ DPI at their placed size.

1. Black text and fine lines: Set to Overprint Fill (Window → Attributes). This prevents a white knockout around black elements that can appear as a white halo after printing.

1. Save as: File → Save As → PDF (PDF/X-4 or PDF/X-1a). Embed all fonts. Do not downsample images below 300 PPI.

Setting up your file in Procreate

Procreate's CMYK support is limited but functional for many designs.

1. Canvas settings: Canvas → Canvas Properties → Color Profile → select a CMYK profile
2. Export: Share → PDF or TIFF. In the export settings, select CMYK color space if available
3. For critical color accuracy: Export as TIFF and open in Photoshop to fine-tune before submitting to the printer

Procreate works well for bold, graphic designs and hand-painted aesthetics. For photographic or fine-detail work, Photoshop or Lightroom for editing → Illustrator or InDesign for layout gives more precise control.

Maximizing your sheet: layout for Letter size

A Letter-size sheet is 8.5" × 11". With a ½" margin on all sides, your printable area is 7.5" × 10".

Tips for efficient sheet layout:

• Nest designs tightly — leave ¼" between individual design elements for cutting clearance, but no more
• Rotate designs to fit more on one sheet. A rectangular design that fits as landscape may waste less space than portrait
• Repeat small designs — if you're creating a motif that you'll use repeatedly (e.g., a 2" botanical illustration), fill the sheet with 12–16 copies rather than one large placement
• Include test elements — add a small test strip of critical colors to a corner of your first run. After firing, you'll have a color reference specific to your printing setup and glaze combination
• Label your sheet — include the design name, color profile, and date in a margin area outside the printable zone. Your printer may trim this off, but it helps with recordkeeping for repeat orders

Submitting your file for printing

When you're ready to order, here's what most printers (including me) need:

• Format: PDF preferred, or TIFF/PSD at 300 DPI
• Color mode: CMYK
• Sheet layout: Full Letter size with designs nested inside the printable area
• Fonts: Outlined/embedded (no live text that requires a specific font installation)
• Layers: Flattened or merged unless otherwise requested

If you're ordering custom decals from me directly, you'll upload your file during the ordering process and I'll confirm your layout before printing.

Still working on your design?

If you're at the design stage and want to understand how the finished decal will look on your specific glaze, a test order is the right first step. Order one sheet, fire it on a sample tile with your intended glaze, and use that result to refine your design before a larger run.

Questions about file setup? Contact me — I review files before printing and catch problems before ink hits paper.