The short version: Screen printing needs high-resolution files (300 DPI minimum), separated by color, with text converted to outlines. Vector files work best. If that made no sense — don't worry, we'll walk through it step by step.
File Formats That Actually Work
Not all file types are created equal when it comes to screen printing. Here's the hierarchy:
Best: Vector Files (AI, EPS, PDF)
Why they're ideal: Vector files use mathematical paths instead of pixels, which means they can scale to any size without losing quality. A 2-inch logo can become a 20-inch back print with zero loss in clarity.
When to use: Logos, text-heavy designs, illustrations with solid colors, geometric shapes, line art.
Software: Adobe Illustrator, CorelDRAW, Inkscape (free alternative)
If you're hiring a designer, ask for an Adobe Illustrator (.AI) file with fonts converted to outlines and all colors set to spot colors. This is the gold standard for screen printing.
Good: High-Resolution Raster Files (PSD, PNG)
Why they work: Raster files are made of pixels. As long as there are enough pixels (high resolution), they'll print cleanly.
The critical requirement: 300 DPI at actual print size. This is non-negotiable. A 72 DPI image pulled from a website will look terrible when blown up to print size.
When to use: Photographic elements, complex artwork with textures, designs that started as photos.
How to check resolution:
- Photoshop: Image → Image Size → Check "Resolution" field (should say 300 pixels/inch)
- Mac Preview: Tools → Show Inspector → Look at DPI in "More Info"
- Windows: Right-click file → Properties → Details → Look for "Horizontal/Vertical Resolution"
Avoid: JPG, Low-Res Images, Word/PowerPoint Files
Why they fail:
- JPG files: Compressed format that loses quality with each save. Fine for web, terrible for printing.
- Images from websites: Usually 72 DPI — way too low. They look fine on screens but pixelated when printed.
- Word/PowerPoint: Not designed for print production. Text converts poorly, colors shift, and resolution is unpredictable.
Send us what you have. If your file won't work, we'll let you know what needs fixing. We'd rather help you get it right than reject your order later.
Resolution & Size Requirements
Here's the rule that causes the most confusion: Resolution depends on size.
A 3" × 3" logo at 300 DPI looks great — at 3 inches. Blow it up to 12" × 12" and you now have a 75 DPI image. Pixelated and unusable.
The Math
If your design will print at 12" × 14" (common left chest size):
- Width: 12 inches × 300 DPI = 3,600 pixels wide
- Height: 14 inches × 300 DPI = 4,200 pixels tall
Your file needs to be at least 3,600 × 4,200 pixels to print cleanly at that size.
Common Print Sizes
| Location | Typical Size | Minimum Pixels (at 300 DPI) |
|---|---|---|
| Left Chest | 3.5" × 3.5" | 1,050 × 1,050 px |
| Full Front | 12" × 14" | 3,600 × 4,200 px |
| Full Back | 13" × 16" | 3,900 × 4,800 px |
| Jumbo Print | 17" × 23" | 5,100 × 6,900 px |
Creating a logo at 4" × 4", then scaling it up to 14" × 14" in your design software. The software shows it smooth, but the printer sees a low-res mess. Always create or work at actual print size.
Color Modes & Separation
This is where screen printing gets technical — but stick with me, because understanding this will save you money and get better results.
Spot Colors (What Screen Printers Want)
Screen printing works by layering one color at a time. Each color = one screen = one pass through the press.
In your design software, this means:
- Each color should be on its own layer
- Colors should be solid (not gradients between different colors)
- Use Pantone colors when possible for exact color matching
How to set up spot colors in Illustrator:
- Window → Swatches
- Click swatch library icon → Color Books → Pantone+ Solid Coated (or choose your Pantone system)
- Select colors from the Pantone library
- Make sure each color shows a small white triangle in corner (indicates spot color)
CMYK vs RGB
CMYK (Cyan, Magenta, Yellow, Black): The standard for print. Closer to what screen printing inks look like.
RGB (Red, Green, Blue): For screens. Colors can look different when converted to printable inks.
Our take: If you're using spot colors (recommended), this matters less. If you're submitting a raster file, CMYK is safer. But we'll convert and proof regardless — what you see in the mockup is what you'll get.
Gradients & Halftones
Simple gradients: A fade from blue to white? Totally doable. We'll halftone it (convert to dots) during screen prep.
Complex gradients: A 5-color blend across a sunset photo? That's pushing it. Screen printing isn't built for photo-realistic color blends. Better options exist (DTG printing, sublimation).
Our recommendation: If your design has gradients, send it over and ask. We'll tell you honestly if it'll work or if you need to simplify.
Dark Garments: The Hidden Color
Printing on black shirts? Navy? Dark red? You need an underbase.
An underbase is a layer of white ink printed first, then your colors print on top. Without it, your colors disappear into the dark fabric.
What this means for you:
- Dark garments add one color to your count (the white underbase)
- A 2-color design on dark = 3 colors total (white + your 2 colors)
- This affects pricing — see pricing page
Colors that need underbase: Black, navy, dark gray, dark red, forest green, brown — basically anything darker than a medium shade.
Design Tip: Some designs work better with the dark garment color showing through. Instead of printing a solid white underbase everywhere, we can knock out areas and let the shirt color be part of the design. Ask us about this when submitting — it can save you a color.
What to Avoid (Common Deal-Breakers)
1. Too Many Colors
Each color adds cost and complexity. Stick to 6 colors or fewer. Beyond that, prints get expensive and colors can look muddy on fabric.
2. Tiny Text
Minimum readable size: 8pt (about 0.11 inches tall)
Anything smaller turns into blurry blobs. Script fonts need to be even larger (10-12pt minimum) because thin strokes fill in.
3. Super Fine Lines
Minimum line thickness: 1pt (0.014 inches)
Thinner lines break up during printing or don't hold ink properly. This especially affects delicate linework and script fonts.
4. Unlicensed Images or Fonts
We can't print copyrighted material without permission. This includes:
- Images pulled from Google/Pinterest without license
- Brand logos (Nike, Disney, etc.) without authorization
- Commercial fonts you don't own
If you're unsure about licensing, ask before we start production.
Pre-Flight Checklist: Is Your Artwork Ready?
✓ Artwork Readiness Checklist
What Happens After You Submit
Here's our process once you send artwork:
- File Review (1-2 business days): We check your files for print-readiness. If something won't work, we'll reach out with specifics.
- Digital Mockup: We create a mockup showing exactly how your design will look on the garment. This is your chance to catch issues.
- Your Approval: You review and approve the mockup. Once approved, we move to production.
- Screen Prep & Printing (2-3 weeks): We create screens, mix inks to match your colors, and run your order.
- Quality Check & Ship: Every piece is inspected before packing and shipping.
Not sure if your files will work? Send them over before placing an order. We'll review for free and let you know what (if anything) needs adjusting. Email files to info@cowdogprint.co or submit through our quote form.
Still Not Sure? We Can Help.
Look, artwork prep can be confusing. You're a business owner, musician, artist — not a print technician. That's our job.
Here's what we can do:
- Review your existing files and tell you exactly what needs fixing
- Make minor adjustments (convert text to outlines, color separation, etc.) at no charge
- Connect you with designers we trust if you need artwork created from scratch
- Consult on design choices (colorways, placement, garment selection) to maximize quality
We want your merch to look incredible. That starts with getting the artwork right.
Ready to Get Your Artwork Reviewed?
Send us your files and we'll let you know if they're print-ready — or what needs adjusting. Free review, no obligation.