What Makes Artwork Print-Ready: The Preflight Checklist

Print-ready artwork passes preflight without errors and produces prints that match the proof. It has correct resolution (300 DPI at final size), proper color space (CMYK for offset, RGB accepted for DTG/DTF), bleed and safe margins, no low-res linked images, outlined fonts, and no live effects that could render differently on output. A file that looks perfect on screen can still fail at print if resolution, bleed, or color mode is wrong.

Different print processes have different requirements. Offset printing demands CMYK with bleed and crop marks. Screen printing needs spot colors or halftones with registration marks. DTF requires transparency and RGB (or CMYK). Sublimation needs RGB raster at 300+ DPI. Understanding what your printer expects prevents costly rework and delays.

Resolution: 300 DPI at Final Print Size

Resolution is pixels per inch at the final printed size. A 10×10 inch print at 300 DPI requires a 3000×3000 pixel image. If you scale a 1000×1000 pixel image to 10×10 inches, effective resolution drops to 100 DPI, and the print will look pixelated. Check resolution by dividing pixel dimensions by print size: 3000 pixels ÷ 10 inches = 300 DPI.

Vector artwork (SVG, PDF, EPS, AI) is resolution-independent—it scales without quality loss. Raster artwork (PNG, JPG, TIFF, PSD) has fixed resolution. If your design contains embedded raster images (a photo placed in an Illustrator file), check the resolution of those images at their placed size, not their original size. An image that is 300 DPI at 5 inches but scaled up to 10 inches in the layout is only 150 DPI at print size.

Some print processes tolerate lower resolution. Large-format banners (viewed from 10+ feet away) can use 150 DPI. Screen-printed posters can use 200 DPI if the line screen is coarse (35–45 LPI). But for most commercial printing—apparel, signage, packaging, marketing materials—300 DPI is the minimum. Going higher (600 DPI) adds file size without visible improvement at typical viewing distances.

Bleed and Safe Margins

Bleed is extra artwork that extends beyond the trim edge, so when the print is cut, there are no white borders if the cut is slightly misaligned. Standard bleed is 3mm (0.125 inches) on all sides. If your design has a background color or image that goes to the edge, extend it 3mm past the trim line. If the design has a white border, no bleed is needed—the border absorbs any cutting tolerance.

Safe margin (also called live area or safety zone) is the region where important content—text, logos, faces—should stay. Standard safe margin is 3mm (0.125 inches) inside the trim edge. If you place text right at the trim line, it may get clipped during cutting. Keep all critical elements at least 3mm inside the final trim size.

Bleed and safe margin together create a 6mm buffer: 3mm of bleed outside the trim, 3mm of safe margin inside. For a business card trimmed to 3.5×2 inches, the design canvas should be 3.75×2.25 inches (with bleed), and text should stay within 3.25×1.75 inches (safe area).

Color Space: CMYK vs RGB

Offset printing, commercial digital presses, and some large-format printers use CMYK inks. If you send an RGB file, the printer's RIP converts it to CMYK, and colors shift—especially bright blues, oranges, and greens, which fall outside CMYK gamut. To control the conversion, convert to CMYK in your design software before export, then proof the colors on a calibrated monitor or with a printed proof.

DTG (direct-to-garment), DTF, and sublimation printers typically accept RGB because their RIPs are profiled for RGB input. Sending a CMYK file may cause the RIP to interpret it as RGB anyway, leading to unexpected color. Check your printer's specifications—most apparel decorators prefer RGB; most commercial printers prefer CMYK.

Screen printing with spot colors requires spot color swatches, not RGB or CMYK process colors. In Illustrator or CorelDRAW, assign each design element to a named spot color (Pantone, or custom-named swatch). Do not use RGB fills—spot separations rely on swatch names, not color values. For more on screen print separations, see manual and automatic color separation workflows.

Fonts: Outlined or Embedded

Live text (editable font objects) will not print correctly if the printer does not have the font installed. Characters will reflow, substitute with a default font, or disappear. Two solutions: outline the text (convert it to vector shapes), or embed the font in the PDF.

Outlining is safer—it guarantees the text will appear exactly as designed, with no font dependencies. In Illustrator, select all text and choose Type → Create Outlines. In Inkscape, use Path → Object to Path. Outlined text cannot be edited as text, so save a copy of the source file with live text before outlining.

Embedding fonts works for PDFs. When you export a PDF from Illustrator, InDesign, or Affinity Publisher, check the option to embed fonts (usually enabled by default). This includes the font data in the PDF so the printer can render it. Embedding fails if the font license prohibits it—some fonts (especially free web fonts) have embedding restrictions. If embedding fails, outline the text instead.

Linked Images and Embedded Assets

Design files (AI, INDD, PSD) often link to external image files instead of embedding them. If you send the design file without the linked images, the printer sees only low-res previews, and the print will be pixelated. Package all assets before sending: File → Package in InDesign, File → Package in Illustrator (CC 2019+), or manually collect all linked files into a folder.

For PDFs, embedding is automatic—images are included in the PDF when you export. Check the PDF file size: if it is only 100 KB for a full-color design, images may not be embedded. Re-export with high-quality settings (no downsampling, no compression for critical images).

Check image resolution at placed size. In InDesign or Illustrator, the Links panel shows effective PPI (pixels per inch) for each placed image. If an image shows 150 PPI effective, it is too low for most printing. Replace it with a higher-resolution version, or scale it down in the layout to increase effective PPI.

Artboard and Page Size

Set the artboard or page size to match the final print size plus bleed. If the print is 4×6 inches with 3mm bleed, the artboard should be 4.25×6.25 inches. If you leave the artboard at the default (8.5×11 inches letter size), the printer may assume you want to print on 8.5×11 inch stock, or they may scale the design down to fit the intended size, shrinking everything including bleed and safe margins.

For multi-page documents (brochures, booklets), ensure all pages have consistent size and bleed. InDesign and Affinity Publisher handle this automatically if you set bleed in the document setup. For single-page designs in Illustrator, use Object → Artboards → Fit to Artwork Bounds, then manually expand the artboard by 3mm on all sides for bleed.

File Formats for Different Processes

Offset and commercial digital printing: PDF/X-1a or PDF/X-4 (CMYK, fonts outlined or embedded, bleed included). Do not send native files (AI, INDD) unless the printer requests them.

Screen printing: High-res PDF or EPS with spot colors, or separated TIFF files (one per color). Some shops accept PNG if you are outsourcing separation to them. Include registration marks if you separated the file yourself.

DTF and sublimation: PNG-24 (with transparency for DTF) at 300 DPI, or high-res PDF. RGB color space. For DTF, ensure the file has no background (covered in DTF white underbase issues).

Large-format and signage: PDF or TIFF at 150–300 DPI, depending on viewing distance. RGB or CMYK depending on the printer (ask first).

For vector-to-raster conversion, use SVG to PNG conversion at 300 DPI. For raster-to-vector (when you have a low-res logo and need it scaled up), use logo vectorization. For batch conversion workflows, see batch file processing strategies.

Preflight Checklist Before Sending Files

Run through this checklist for every print job. Most design software (InDesign, Illustrator, Affinity Publisher) has a built-in preflight panel that flags common errors.

• Resolution: 300 DPI at final size for all raster elements (150 DPI for large-format)
• Color mode: CMYK for offset, RGB for apparel, spot colors for screen print
• Bleed: 3mm on all sides where design goes to the edge
• Safe margin: 3mm inside trim for text and logos
• Fonts: outlined or embedded
• Linked images: none missing, all at correct resolution
• Artboard size: matches final trim + bleed
• No RGB colors in spot-color screen print files
• No live effects (drop shadows, blurs) that may render differently—rasterize or flatten them
• Export format: PDF/X or high-res PNG/TIFF as required by printer

For DTF-specific file prep, read why DTF prints white boxes and how to fix them. For screen print separations, see spot color separation workflows. For comparing print processes, see sublimation, DTF, and UV DTF.