Print the same design on the same DTG machine, and you can still end up with two totally different shirts. One looks crisp and premium. The other looks soft, blurry, or slightly “cheap,” even though the artwork looked fine on your screen. In most cases, the printer is not the problem. The file you send is.
DTG (direct-to-garment) printing does not repair weak artwork. It prints exactly what you provide, including jagged pixels, compression marks, and low resolution. If you send the wrong file type or the wrong size, your print quality drops fast.
In this guide, you will learn when to use vector files, when raster files work better, and the simple steps that keep DTG prints sharp. And if your logo only exists as a small JPG, WhatsApp image, or screenshot, a professional vector conversion gives you a clean master file you can reuse for every future print, without rework.
- DTG Printing in Simple Words
- What Is a Raster File?
- What Is a Vector File?
- The Biggest Difference: Scaling and Edge Quality
- Best File Types for DTG: What Shops Usually Ask For
- When Raster Is the Right Choice
- When Vector Is the Best Choice
- Common DTG File Mistakes That Ruin Prints
- When Getting Professional Artwork Help Becomes the Smart Move
DTG Printing in Simple Words
What DTG Printing Actually Does
DTG (direct-to-garment) printing works like a high-end inkjet printer for T-shirts. The machine sprays water-based ink directly onto the fabric, then heat-cures it so the design bonds properly and lasts. Because it prints straight onto the shirt, DTG can capture smooth gradients, tiny details, and photo-style artwork when the file is prepared correctly.
Why Artwork Quality Matters So Much
DTG does not “clean up” your design. It prints exactly what you provide, including fuzzy edges, pixel noise, and compression marks. Fabric texture also makes weak edges look worse, so a file that looks okay on a phone can still print soft or rough on a shirt.
The Most Common Problem: The Wrong Kind of File
Many customers send a small JPG from Google, a screenshot, or a WhatsApp-forwarded logo and expect it to print sharply at 10–12 inches wide. DTG cannot invent missing detail, so the result comes out blurry or uneven. That is why choosing the right file type matters before you print.
What Is a Raster File?
Raster Files Are Made of Pixels
A raster file is an image built from tiny squares called pixels. Each pixel holds a color value, and together these pixels form the picture you see. When you zoom in on a raster image, you eventually start seeing those little blocks, especially around edges and text. This pixel-based structure is why raster quality depends heavily on resolution and final print size.
Common Raster Formats You’ll See in DTG
Most customers send raster files without realizing it. The most common raster formats include JPG/JPEG, PNG, TIFF, and PSD (Photoshop files). These formats are everywhere because phones, cameras, and most design apps export raster images by default.
When Raster Works Best
Raster files shine when you print photos, realistic artwork, smooth shading, and gradients. If you want a portrait on a shirt or a detailed illustration with lots of color blending, raster can work beautifully, as long as the file is large enough and clean.
The Big Problem: Enlarging Makes It Look Worse
The weakness of raster is simple: if you enlarge a small image, you stretch the pixels. That creates softness, jagged edges, and sometimes a grainy or “dirty” look. A design can look sharp on a phone screen because the phone displays it small. But when you print it on a shirt at 10–12 inches wide, the missing detail shows up immediately.
Quick Example
A small JPG logo might look perfect in an email signature. Print it on a DTG shirt, and the edges suddenly look fuzzy and uneven, especially on fabric texture.
What Is a Vector File?
Vector Files Use Shapes, Not Pixels
A vector file builds artwork using paths, points, and shapes instead of pixels. Think of it like drawing with perfect mathematical lines and curves. Because the design is based on shapes, the file does not “break into blocks” when you zoom in. It simply redraws the lines smoothly at any size.
Common Vector Formats
You will usually see vector artwork in formats like AI (Adobe Illustrator), EPS, SVG, and vector PDF. (Important: a PDF can be vector or raster depending on how someone created it, so you cannot assume every PDF is a true vector file.)
When Vector Is the Best Choice
Vector files work best for logos, text, badges, icons, and any design that needs clean edges. DTG printing benefits from this because sharp outlines and crisp lettering look more professional on fabric. Vector also makes it easy to change colors, adjust thickness, and create different sizes for left chest, full front, or back prints without quality loss.
Why Vectors Stay Sharp at Any Size
Since vector artwork is math-based, it scales up or down without losing detail. A logo can go from a small sleeve print to a big back print and still look clean and smooth. This saves you from redoing artwork every time you change placement or size.
A Quick Note About Photo-Real Designs
Vectors are not always the best fit for photo-real images or complex shading. You can still prepare those designs well, but they often work better as high-resolution raster files instead of forcing everything into vector shapes.
The Biggest Difference: Scaling and Edge Quality
Raster Depends on Resolution and Print Size
Raster files only look sharp when they have enough pixels for the size you want to print. If you stretch a small image bigger, you spread the same pixels over a larger area. That is when edges turn soft, curves look jagged, and fine details start to disappear. DTG makes this worse because fabric texture already softens edges, so low-resolution artwork shows up quickly on a shirt.
Vector Stays Crisp When You Resize
Vector files behave differently. When you resize a vector, the software redraws the shapes cleanly at the new size. That is why logos and text stay sharp whether you print them small on a sleeve or large on the back.
DPI Explained Simply (and Why DTG Cares)
DPI means dots per inch. It tells you how much detail your raster image has for each inch of print. For DTG, a common safe target is 300 DPI at the final print size. That means you should decide the print size first (example: 12 inches wide), then make sure the file has enough pixels to stay at 300 DPI at that size. If you only have a small file, you cannot “add” real detail by increasing DPI.
Simple Rule
If you might resize a design, start with a vector master. Then export a properly sized, high-resolution file for DTG when you are ready to print.
Best File Types for DTG: What Shops Usually Ask For
DTG-Friendly Files Printers Prefer
Most DTG shops ask for a PNG with a transparent background because it drops cleanly onto any shirt color. Many also accept a PSD (Photoshop file), especially if it has layers they can adjust. Some shops take high-resolution TIFF files too, mainly for photo-heavy designs where you want maximum quality and minimal compression.
Why Transparent Backgrounds Matter
A transparent background prevents the classic mistake: a white or colored “box” printing around your design. With a clean PNG transparency, the printer only outputs the artwork, not the background behind it. This makes logos, text, and cutout designs look professional, especially on dark garments.
Where Vector Fits In
Even when a shop asks for PNG or PSD, vector still plays a major role. A vector file often serves as the master artwork because it scales perfectly and keeps edges crisp. You can then export a perfect, correctly sized PNG at high resolution for DTG whenever you need it.
Quick Note About PDFs
Do not assume “PDF” means vector. Some PDFs contain raster images placed inside a PDF wrapper. A true vector PDF stays sharp when you zoom in; a raster-based PDF turns pixelated. Always check before you send it.
When Raster Is the Right Choice
Best Use Cases for Raster
Raster files are the right choice when your design is photo-based or has lots of realistic detail, like portraits, painted artwork, complex textures, and smooth gradients. DTG handles these styles well because it can print full color and soft transitions, as long as the file is strong enough.
Must-Haves for Clean DTG Results
To print raster artwork sharply, you need the correct final size and enough resolution. Aim for 300 DPI at the exact print size you plan to use (for example, a 12-inch wide front print should still be 300 DPI at 12 inches). Keep compression low, because heavy compression creates blurry edges and ugly artifacts that DTG will print exactly as they appear.
Avoid These Common “Bad Sources”
Do not use screenshots, social media downloads, or WhatsApp-forwarded images. These files look okay on a phone, but they usually lose detail, get resized, and pick up compression damage that turns into a soft, dirty print on fabric.
When Vector Is the Best Choice
Best Use Cases for Vector
Vector files work best for logos, typography, icons, badges, and flat-color designs. If your artwork has clean lines, simple shapes, or lettering that must look sharp, vector gives you the strongest starting point. DTG prints fine details, so crisp edges and clean curves make a big difference in how “premium” the final shirt looks.
Why Vector Improves Print Results
Vector artwork gives you cleaner outlines and sharper text because it does not rely on pixels. It also makes edits easier. You can change colors, adjust stroke thickness, fix spacing, and refine edges without damaging quality. That matters when you want consistent branding across different garments and print runs.
Perfect for Multiple Print Sizes
Vector becomes especially useful when you need the same design in different placements. A logo might go on a left chest, then appear larger on the back, and maybe smaller on a sleeve. With vector, you resize once and keep it crisp every time. You avoid the common problem of stretching a small raster logo and ending up with soft, jagged edges on fabric.
Common DTG File Mistakes That Ruin Prints
Low Resolution or Wrong Size
Small files printed big turn blurry fast. Always match the artwork to the final print size.
JPG Compression Damage
JPGs often add blocky edges and halos around text and shapes. Re-saved JPGs look even worse in DTG.
No Transparency
A non-transparent background can print as an ugly box. Use a transparent PNG when needed.
Too-Thin Lines or Tiny Text
Fabric texture breaks thin strokes and fills in small text. Keep details bold enough to survive printing and washing.
Poor Contrast on Shirt Color
Light-on-light and dark-on-dark designs look weak. Adjust outlines and colors for the garment.
Screen Colors vs Printed Output
What you see on screen can shift on fabric. DTG often starts in RGB, but inks and fabric limit brightness, so always check a proof or test print for critical jobs.
When Getting Professional Artwork Help Becomes the Smart Move
The Common Reality
Most DTG problems start with the artwork, not the printer. Many logos arrive as small JPGs or PNGs pulled from a website, copied from an email signature, or forwarded through WhatsApp. They can look “fine” on screen, but they do not hold up when you print them at 10–12 inches wide.
Why DIY Fixes Often Cost More
You can try to clean up a low-res file yourself, but the risk is real. You may waste test prints and blank shirts, spend hours going back and forth on edits, and still end up with uneven outlines or jagged edges that make the final print look cheap. For paid orders, those delays and reprints hit your profit and your deadlines.
Why Professional Vector Conversion Pays Off
A professional vector conversion usually acts like a one-time repair. You get a clean, scalable master file that stays sharp at any size, so you can reuse it for every future DTG order. Proofs also look cleaner, which speeds up customer approvals. And when you scale up for large back prints, you avoid the surprise of blurry edges. If you print often or sell to customers, getting a clean vector version early usually saves money.
Conclusion
DTG can produce stunning results, but it only prints what you provide. Use raster files for photos and detailed artwork, and use vector files for logos, text, and clean line designs. The key is to match the file to the job, then prepare it at the right size. Before you print in bulk, confirm your final dimensions, aim for 300 DPI for raster artwork, and use transparent backgrounds when needed so you do not end up with a background box.
If you feel unsure about your file, do not guess. A quick check now can save you from wasted shirts and reprints later. If you want clean, print-ready results fast, our professional vector artwork conversion and DTG file prep services can help. Send your artwork for review, and we can convert it into a crisp vector master and export DTG-ready PNGs so you can print with confidence.